Conference Committee and Related Procedures: An Introduction

Summary: The House and Senate must pass the same bill or joint resolution in precisely the same form before it can be presented to the President. Once both houses have passed the same measure, they can resolve their differences over the text of that measure either through an exchange of amendments between the houses or through the creation of a conference committee.

Summary: The House and Senate each have an opportunity to amend the other chamber's amendments to a bill; thus, there can be House amendments to Senate amendments to House amendments to a Senate bill. If either chamber accepts the other's amendments, the legislative process is complete. Alternatively, each house may reach the stage of disagreement at any time by insisting on its own position or by disagreeing to the position of the other chamber. Having decided to disagree, they then typically agree to create a conference committee to propose a single negotiated settlement of all their differences.

Summary: Conference committees are generally free to conduct their negotiations as they choose, but under the formal rules they are expected to address only the matters on which the House and Senate have disagreed. Moreover, they are to propose settlements that represent compromises between the positions of the two houses. When they have completed their work, they submit a conference report and joint explanatory statement, and the House and Senate vote on accepting the report without amendments. Only after the two houses have reached complete agreement on all provisions of a bill can it be sent to the President for his approval or veto.

This report is a brief summary of House and Senate procedures for reaching agreement on legislation. It discusses the provisions of House Rule XXII and Senate Rule XXVIII as well as other applicable rules, precedents, and practices. The report focuses on the most common and customary procedures. There are many exceptions, complications, and possibilities that are not addressed, and the House and Senate may modify or waive their procedures by unanimous consent or by other means.

The House and Senate must pass the same bill or joint resolution, and they must reach full and precise agreement on its text before it is submitted to the President for his approval or veto. The same requirements apply to a concurrent resolution and a joint resolution proposing a constitutional amendment, although neither receives presidential action.

At some stage of the legislative process, therefore, the House must pass a Senate bill or the Senate must pass a House bill. The simplest way of meeting this requirement is for one house to pass its own bill and send it to the "other body," which then considers and passes it, with or without amendments. Frequently, however, House and Senate committees each develop their own bills on the same subject. In these cases, one house often debates and amends the bill reported by its committee but then amends and passes the corresponding bill that the other chamber has already passed.

For example, after the House passes a bill, it frequently takes up a bill on the same subject that it has already received from the Senate. The House then amends the Senate bill by striking out the text passed by the Senate (striking out all after the enacting clause) and replacing it with the text of the House bill it has just passed. The House then passes the amended Senate bill. In this way, the House passes two bills with exactly the same text, but the Senate bill is the one likely to become law because both houses now have passed it, although with different provisions. Much the same thing could happen in the Senate. After considering its own bill, the Senate, by unanimous consent, could take up and pass the House bill after amending it with the text of the Senate-passed bill. Because this action would take unanimous consent in the Senate, however, the Senate might choose instead to begin consideration of the similar House bill. The floor manager could offer as the first amendment to the House bill a full-text substitute consisting of the text of the Senate bill.

This process is usually routine, but it can become more complicated. For instance, the Senate may pass one bill on several related matters before the House passes two bills of its own that address the same subjects. After the House passes its two bills, it may take up the one Senate bill and replace the text of that bill with the texts of both of its own bills. In other instances, the House and Senate may confront political and procedural situations that make it convenient for them to include their versions of legislation on one subject as amendments to some third bill on an unrelated subject that serves as a convenient "vehicle." Such arrangements can be necessary because the House and Senate cannot begin the formal process of resolving their policy differences until these differences are embodied as amendments by one house to the version of the same bill as passed by the other.

After one house passes a bill and the other then passes it with amendments, the House and Senate may attempt to resolve the differences between their positions. When confronted with a major bill, the two houses have historically created a conference committee for this purpose. However, a conference may not be necessary if they can reach an agreement through informal negotiations and an exchange of amendments between the houses.

The amendments of one house to a bill from the other may be amended twice as the bill is sent ("messaged") back and forth between the House and Senate. Suppose, for example, that the Senate passes a House bill with amendments. The House can accept (concur in) the Senate amendments, in which case the differences are resolved. Alternatively, the House can amend the Senate amendments (concur in the Senate amendments with amendments). These House amendments are first degree amendments between the houses. The Senate can then accept (concur in) the House amendments to the Senate amendments, which would produce agreement. Or the Senate can concur in the House amendments to the Senate amendments with further Senate amendments, which are amendments in the second degree.

At this stage, the House can concur in the most recent Senate amendments, but it cannot propose new House amendments to them because they would be third degree amendments, which are not permitted. (Of course, exactly the same process can occur in reverse if the House passes a Senate bill with amendments.) In both chambers, the prohibition on third degree amendments between the houses can be waived. The House might do this by special rule, suspension of the rules, or unanimous consent. In the Senate, unanimous consent is necessary to agree to an amendment in the third degree, unless the House has already waived the rule, in which case further degrees of amendment are permitted in the Senate.

If the House and Senate adamantly defend their last amendments, they can send the bill back and forth several more times. In the unlikely event that neither house retreats from its last position or is willing to discuss a compromise in conference, the bill ultimately dies. It cannot be shuttled back and forth indefinitely.

This process rarely results in stalemate, because the two houses either reach agreement or decide to submit their differences to a conference committee. However, an exchange of amendments sometimes takes the place of a conference. Once the two houses pass their versions of the same bill, the members and staff of the House and Senate committees of jurisdiction often meet informally to compare the two versions and discuss a compromise. If they reach an agreement that other concerned Representatives and Senators also accept, the House can, for example, concur in the Senate amendment with a House amendment that embodies the negotiated agreement. If the Senate then accepts (concurs in) this House amendment, the House and Senate have resolved their differences through the informal equivalent of a conference committee.

Considering Amendments from the Other House

House amendments to a Senate bill (or House amendments to Senate amendments to a House bill) are privileged for floor action by the Senate. This means there is no debate on whether to take up the House amendment. Instead, a Senator, most often the majority leader, typically requests that a House amendment be laid before the Senate. Motions to dispose of the House amendments—such as motions to concur or to concur with amendments—are debatable and, therefore, subject to filibusters. It is possible for the majority leader to move that the Senate concur in the House amendment and then propose motions that preempt all other available motions. This is often referred to as "filling the tree" on a motion to concur. If the majority leader can garner the necessary support to end debate on the motion to concur (60 Senators, assuming no vacancies), then both further amendment to the House amendment and extended debate can be avoided. The Senate sometimes arranges to consider a House amendment by unanimous consent.

Like the Senate, the House sometimes acts on Senate amendments by unanimous consent. Until the House officially disagrees to Senate amendments to a House bill (or Senate amendments to House amendments to a Senate bill), these amendments are usually not privileged for consideration on the House floor. No motion is in order to concur in the Senate amendments, with or without amendments. When there is little or no controversy, the House often accepts or amends the Senate amendments by unanimous consent. Otherwise, the House can usually do so only through a motion to suspend the rules or under a special rule recommended by the Rules Committee and adopted by the House. A motion that is privileged at this stage is a motion to disagree to the Senate amendments and go to conference, but this motion must be made at the direction of the committee that originally reported the bill to the House.

Both houses cannot consider the same bill at the same time, because the House or Senate can act only if it has the "papers." The papers are comprised of the official copy of the bill as passed by the house in which it originated, the official copies of amendments by either house, and the messages by which each house informs the other of the actions it has taken. After one house acts on a bill or amendments from the other, it returns all the papers with an accompanying message describing its action. Thus, the House and Senate always act in sequence as custody of the papers changes hands.

Before a conference committee is created to resolve disagreements between the two houses, the House and Senate must each state disagreement over a bill, either by disagreeing to the amendments of the "other body" or by insisting on its own amendments. So long as one house concurs in the amendments of the other and proposes its own amendments, there is no formal disagreement. But at any point during an exchange of amendments between the House and Senate, either house can propose that they can go to conference instead.

The two houses usually decide in one of two ways to establish a conference committee. When the Senate passes a House bill with amendments, for example, it can immediately insist on its amendments and request a conference with the House. The House almost always agrees to the conference, although it need not do so—for example, it could simply agree to the Senate amendments instead. At other times, however, when the Senate passes a House bill with amendments, it may merely send back the bill and the amendments in the hope that the House will accept the Senate's amendments, making a conference unnecessary. If the House does not accept the amendments, it can disagree to them and request a conference. The Senate normally then insists on its amendments and agrees to the conference, after which it informs the House and returns the papers. Of course, the equivalent of either sequence of events may occur after the House passes a Senate bill with amendments.

Both chambers sometimes agree by unanimous consent to the necessary procedural steps to send a measure to conference. In the House, if there is an objection to the unanimous consent request, then a privileged motion can be made, at the direction of the committee(s) of jurisdiction, to disagree to the Senate amendment (or insist on the House amendment) and request (or agree to) a conference with the Senate.

If unanimous consent cannot be reached in the Senate, then a motion can be made to authorize a conference committee, which is subject to debate under regular Senate rules. If a cloture motion to end debate is filed on this motion, however, it matures after just two hours of debate. If three-fifths of the Senate agrees to invoke cloture, then the Senate could immediately vote to approve the motion to authorize a conference. No further debate of the motion would be in order.

Each house usually appoints its conferees (also known as managers) immediately after deciding to go to conference. The Speaker appoints House conferees. The Senate frequently decides, by unanimous consent, to authorize the presiding officer to appoint "the managers on the part of the Senate." The Senate could also empower the presiding officer to appoint conferees, or appoint conferees directly, through the motion to authorize a conference, discussed above. The chairman and ranking minority member of the committee or subcommittee that reported the bill are almost always conferees. They also play a major part in deciding who else is appointed. The committee or subcommittee leaders usually prepare a list of conferees from their chambers that the Speaker normally accepts and the presiding officer of the Senate always accepts. The party leaders may also become involved in selecting conferees, especially if the bill is particularly important, if it was reported by two or more committees, or if amendments to the bill from the other house touch the jurisdiction of more than one committee.

Most conferees are members of the committee that reported the bill. In the case of a bill that involves the jurisdiction of more than one committee, members of each committee are often appointed as conferees with authority only to negotiate an agreement with respect to the subjects or provisions of the bill that fall within the jurisdiction of their committees. Thus, some members may be designated as conferees for purposes of the entire bill while others are appointed only to address a specific section or title. Representatives may also be appointed as conferees for limited purposes when the Senate proposes a nongermane amendment that is within the jurisdiction of another House committee. In addition, the Speaker may appoint other Representatives who, for example, offered important floor amendments. The list of conferees generally reflects the party balance in each house.

The House and Senate do not have to appoint the same number of managers, and they frequently do not. House conferees vote as a delegation, as do Senate conferees, and a majority of each delegation must sign the conference report. Thus, three Representatives have the same voting power in conference as 30 Senators. Each house is likely to appoint a larger number of conferees when the bill involves the jurisdiction of more than one of its standing committees.

A Representative or Senator may move to instruct the conferees from his or her chamber immediately after that house agrees to go to conference but just before the conferees are appointed. For example, the House can instruct its managers to insist on the House position on a particular amendment, or the Senate can instruct its managers to recede to the House position on another amendment. However, instructions to conferees are never binding; no point of order lies against a conference report that is inconsistent with House or Senate instructions to its conferees. The House can also instruct its conferees if they do not report within 45 calendar days and 25 legislative days after being appointed (or 36 hours after being appointed during the last six days of a session).

Conference committee meetings are open to the public unless the conferees vote to close them, and the House must vote to authorize its conferees to do so. Both chambers also have guidelines concerning conference meetings, generally encouraging frequent meetings with open discussions, but these guidelines are often waived or in some cases are not procedurally enforceable.

Beyond these guidelines, there are virtually no House or Senate rules governing conference meetings. Conferees select their own chairman and usually work without formal rules on quorums, proxies, debate, amendments, and other procedural matters. Conferences are negotiating forums, and the two chambers allow conferees to decide for themselves how best to conduct their negotiations. It is most common that a conference committee holds a single public meeting, sometimes for members to offer opening statements only.

However, the House and Senate have important, and roughly the same, rules governing what decisions conferees can make. Conference committees are established to resolve disagreements between the House and Senate over their versions of the same bill. Therefore, the authority of conferees is limited to matters in disagreement. As a general rule, they may not change a provision on which both houses agree, nor may they add anything that is not in one version or the other. Furthermore, conferees are to reach agreements within the "scope" of the differences between the House and Senate positions. For example, if the House appropriates $10 million for some purpose and the Senate amends the bill by increasing the appropriation to $20 million, the conferees exceed their authority if they agree on a number that is less than $10 million or more than $20 million.

It is much harder to determine the scope of the differences when they are qualitative, not quantitative. Also, conferees have more latitude under some circumstances than under others. Under a previous practice, when one house would pass a bill and the other would then pass it with a series of separate amendments—each making a change in a different provision of the bill—these amendments were usually numbered, and it was relatively easy for the conferees to determine the scope of the differences over each amendment. This is generally not true, however, under modern practice when the Senate passes a House bill (or the House passes a Senate bill) with an amendment in the nature of a substitute that totally replaces the text of the bill. In this situation, which arises nearly all of the time, there is only one amendment in conference—for example, a Senate substitute for the House version of a bill. The two versions of the bill can take very different approaches to the same subject, making it difficult for the conferees to isolate every point of agreement and disagreement and to identify the scope of each disagreement. Under these circumstances, the conferees may write their own conference substitute, so long as it is a germane modification of the House and Senate versions.

If a conference agreement exceeds the scope of the differences or deals with a matter that is not in disagreement, the conference report is subject to a point of order when the House or Senate considers it. The House, however, typically protects a conference report against points of order by adopting a resolution reported by the Rules Committee waiving the applicable rules. The Senate, meanwhile, interprets the authority of its conferees generously, especially when they develop a conference substitute. Furthermore, the Senate can waive its rule with a three-fifths vote of Senators duly chosen and sworn (60 Senators if there are no vacancies).

The authority of Senate conferees is further limited by Senate Rule XLIV, paragraph 8. Under this rule, a Senator can raise a point of order against discretionary and mandatory spending provisions of a conference report if they constitute "new directed spending provisions," or what are sometimes called "air drops." Paragraph 8 defines a "new directed spending provision" as follows:

any item that consists of a specific provision containing a specific level of funding for any specific account, specific program, specific project, or specific activity, when no specific funding was provided for such specific account, specific program, specific project, or specific activity in the measure originally committed to the conferees by either House.

The Senate can waive these restrictions on the content of conference reports by a three-fifths vote of Senators duly chosen and sworn (60 Senators assuming no vacancies).

When the conferees reach full agreement, their staffs prepare a conference report that states how they propose to resolve each of the disagreements. Accompanying the report itself is a joint explanatory statement (also known as the statement of managers), which describes the various House and Senate positions and the conferees' recommendations in more detail. A majority of the House managers and a majority of the Senate managers must sign both the conference report and the joint explanatory statement. House rules require that House conferees be given an opportunity to sign the conference agreement at a set time and place. At least one copy of the final conference agreement must be made available for review by House managers with the signature sheets. Each chamber then debates and votes on the conference report in turn.

At the conclusion of a successful conference, the papers usually change hands. The conferees from the house that requested the conference bring the papers into conference and then turn them over to the conferees from the other house. Thus, the house that agreed to the conference normally acts first on the conference report. However, this is a practice that is not required by House or Senate rules.

The Senate usually takes up a conference report by unanimous consent, although a Senator can make a nondebatable motion to consider it. The report may be called up at any time after it is filed, but it is not in order to vote on the adoption of a conference report unless it has been available to Members and the general public for at least 48 hours before the vote. (This requirement can be waived by three-fifths of Senators duly chosen and sworn or by joint agreement of the majority and minority leaders in the case of a significant disruption to Senate facilities or to the availability of the internet.) Under Senate rules, a report is considered to be available to the general public if it is posted on a congressional website or on a website controlled by the Library of Congress or the Government Publishing Office.

When considered on the Senate floor, a conference report is debatable under normal Senate procedures; it is subject to extended debate unless the time for debate is limited by unanimous consent or cloture or if the Senate is considering the report under expedited procedures established by law (such as the procedures for considering budget resolutions and budget reconciliation measures under the Budget Act). Paragraph 8 of Senate Rule XXVIII states that, if time for debating a conference report is limited (presumably by unanimous consent), that time shall be equally divided between the majority and minority parties, not necessarily between proponents and opponents of the report.

A point of order may be made against a conference report at any time that it is pending on the Senate floor (or after all time for debate has expired or has been yielded back if the report is considered under a time agreement). If a point of order is sustained against a conference report on the grounds that conferees exceeded their authority, either by violating the "scope" rule (Rule XXVIII) or the prohibition against "new directed spending provisions" (paragraph 8 of Rule XLIV), then there is a special procedure to strike out the offending portion(s) of the conference recommendation and continue consideration of the rest of the proposed compromise.

Under the procedure, a Senator can make a point of order against one or more provisions of a conference report. If the point of order is not waived (see below), the presiding officer rules whether or not the provision is in violation of the rule. If a point of order is raised against more than one provision, the presiding officer may make separate decisions regarding each provision. After all points of order raised under this procedure are disposed of, the Senate proceeds to consider a motion to send to the House, in place of the original conference agreement, a proposal consisting of the text of the conference agreement minus the provisions that were ruled out of order and stricken. Amendments to this motion are not in order, and debate is limited only if it had been limited on the conference report. In short, the terms for consideration of the motion to send to the House the proposal without the offending provisions are the same as those that would have applied to the conference report itself.

If the Senate agrees to the motion, the altered conference recommendation is returned to the House in the form of an amendment between the houses. The House then has an opportunity to act on the amendment under the regular House procedures for considering Senate amendments discussed in earlier sections of this report.

Senate rules also create a mechanism for waiving these restrictions on conference reports. Senators can move to waive points of order against one or several provisions, or they can make one motion to waive all possible points of order under either Rule XXVIII or Rule XLIV, paragraph 8. If the motion to waive garners the necessary support, the Senate is effectively agreeing to keep the matter that is potentially in violation of the rule in the conference report.

In the House, the conference report cannot be considered unless it has been available in the Congressional Record or on the House document repository website for 72 hours. Copies of the report and the statement must also be available to Representatives for at least two hours before they consider it. These availability requirements are sometimes waived by a rule reported by the Rules Committee, and they do not apply during the last six days of a session. Typically, the House calls up a conference report under the terms of a special rule that protects the report against one or more points of order if the Rules Committee reports and the House adopts a resolution waiving the applicable rules.

The House debates a conference report under the one-hour rule, with control of the hour equally divided between the two parties. However, if both floor managers support the report, a Representative opposed to it may claim one-third of the time for debate. At the end of the first hour, the House normally votes to order the previous question, which precludes additional debate. If Representatives could make points of order against a report, sometimes the House first considers and agrees to a resolution, recommended by its Rules Committee, that protects the report by waiving the points of order.

Conference reports are not amendable. Each report is a compromise proposal for resolving a series of disagreements; the House prevails on some questions, the Senate on others. If the House and Senate were free to amend the report, they might never reach agreement. At the end of debate, therefore, each house votes on whether to agree to the report as a whole. However, the house that considers the report first also has the option of recommitting it to conference. But when one chamber acts on the report, it automatically discharges its conferees. As a result, the other house cannot vote to recommit, because the conference committee has been disbanded.

If the House and Senate agree to the conference report, the bill is enrolled (printed on parchment in its final form) and presented to the President for his approval or disapproval.

The report is based upon the original author's interpretation of the rules and published precedents of the two houses and an analysis of the application of these rules and precedents in recent practice (see "Acknowledgements"). Readers may wish to study the provisions of House and Senate rules and examine the applicable precedents—especially in the sections on "Senate Bills," "Amendments Between the Houses," and "Conferences Between the Houses"—in House Practice: A Guide to the Rules, Precedents and Procedures of the House and the corresponding sections on "Amendments Between Houses" and "Conferences and Conference Reports" in Riddick's Senate Procedure (Senate Document No. 101-28). There is also more detailed information on this subject in CRS Report 98-696, Resolving Legislative Differences in Congress: Conference Committees and Amendments Between the Houses , and CRS Report R41003, Amendments Between the Houses: Procedural Options and Effects .


Social Security: Demographic Trends and the Funding Shortfall

Summary: The Social Security program pays monthly benefits to retired or disabled workers and their families and to the family members of deceased workers. Social Security, or Old-Age, Survivors, and Disability Insurance (OAS DI), is intended to operate primarily as a pay-as-you-go system, where program revenues cover program costs. The OASDI program's revenues and costs are largely determined by economic and demographic factors. The Social Security program is experiencing rising costs and relatively stable income, a trend that is projected to continue for several decades. Although economic and program-specific factors affect the balance between program revenues and costs, research has shown demographic factors to be one of the leading contributors to the increasing imbalance between costs and revenues.

Summary: The U.S. population has been experiencing a shift in age structure toward older ages and an increase in the median age, termed demographic aging . Two demographic effects have contributed to this aging over time: decreasing fertility and increasing longevity. While aging reflects a society's shared advances in medical, social, and economic matters, it strains the very social insurance systems that provide social support to the aging population. The post-World War II baby boom generation's effect on OASDI highlights this point. Baby boomers, the relatively large cohort resulting from higher fertility rates from 1946 through 1964, have started to exit the paid labor force and collect Social Security benefits. They are being replaced in the workforce by relatively smaller cohorts resulting from lower fertility rates in subsequent generations. Program costs are also rising as an increasing number of retirees collects benefits for longer time periods. According to the Board of Trustees of the OASDI Trust Funds, costs are expected to rise throughout the 75-year projection period, 2019-2093.

Summary: The Social Security population's changing age distribution is creating a situation in which fewer workers in covered employment are supporting a growing number of people collecting benefits. This relationship is temporarily sustainable, as the OASDI program can draw upon the $2.89 trillion in asset reserves held in the trust funds to augment annual program revenues and fulfill all scheduled benefit payments. However, the OASDI program's ability to pay 100% of scheduled benefits becomes unsustainable when these asset reserves are depleted.

Summary: The Board of Trustees, which oversees the OASDI Trust Funds, projects the funds' assets to be depleted in 2035 due in part to the cumulative strain placed upon the system by an older age distribution. After this, the OASDI program would operate as a strict pay-as-you-go system that can only pay out in benefits what it receives in revenue. Under current laws and projections, the trustees estimate sufficient revenues to be able to pay about 80% of scheduled benefits after asset reserves are depleted. The Social Security program's ability to cover 100% of scheduled benefits depends upon a combination of increased revenues and decreased benefits.

Summary: One set of policy options to address the funding shortfall includes increasing the full retirement age (the age at which a beneficiary is entitled to full benefits) or the earliest eligibility age (the age at which a beneficiary is first entitled to benefits). This set of policy options uses a demographic solution for a largely demographic issue: the projected imbalance between program costs and income.

Summary: Measures that include increasing the retirement ages are estimated to improve the program's long-range financial status but not to prevent trust funds depletion by themselves. Although these adjustments help to reduce rising costs, those costs would still be projected to exceed revenues. This suggests that efforts to avoid depleting the OASDI Trust Funds throughout the trustees' projection period would also be improved by including a revenue-increasing mechanism. In addition, increases in life expectancy are not shared equally within the population; disparities exist when life expectancies are analyzed by sex, race, and income levels. A policy measure that increases Social Security eligibility ages may disproportionally help some beneficiaries and disadvantage others.

The Social Security program, or Old-Age, Survivors, and Disability Insurance (OASDI), pays monthly benefits to retired or disabled workers and their families and to the family members of deceased workers. The OASDI program's ability to meet scheduled benefit payments rests upon sufficient revenues from payroll taxes, taxation on Social Security benefits, and interest earned on trust funds assets. The year 2020 marks the first since 1982 in which the OASDI program's total cost is projected to be greater than its total income. Because of annual cash surpluses amassed in the Old-Age and Survivors Insurance Trust Fund and the Disability Insurance Trust Fund in the period spanning 1983 through 2019, the OASDI program is able to meet its benefit obligations by drawing on these assets to supplement annual revenues. The Board of Trustees of the Federal Old-Age and Survivors Insurance and Federal Disability Insurance Trust Funds estimates that drawing down the trust funds can augment OASDI program revenues and allow it to pay full benefits until 2035. Should the trust funds be depleted in 2035, as the trustees project, the OASDI program would have tax revenues sufficient to pay about 80% of scheduled benefits.

The OASDI program, and its financing, are affected by economic, program-specific, and demographic factors. Economic factors include issues such as productivity, price inflation, unemployment, and gross domestic product; program-specific factors include issues such as covered and taxable earnings, revenues from taxation of benefits, and average benefits indexed to growth in average national wages. Demographic factors include fertility, mortality, and immigration. This report focuses on two demographic factorsâspecifically fertility and mortalityâand how they interact to affect the program's ability to pay full scheduled benefits. The trustees' 2019 Annual Report states the following:

Projected OASDI cost increases more rapidly than projected non-interest income through 2040 primarily because the retirement of the baby-boom generation will increase the number of beneficiaries much faster than the number of covered workers increases, as subsequent lower-birth-rate generations replace the baby-boom generation at working ages. From 2040 to 2051, the cost rate (the ratio of program cost to taxable payroll) generally declines because the aging baby-boom generation is gradually replaced at retirement ages by subsequent lower-birth-rate generations. Thereafter, increases in life expectancy cause OASDI cost to increase generally relative to non-interest income, but more slowly than between 2010 and 2040.

A remaining demographic factorâimmigrationâis not examined in this report because the Board of Trustees analysis shows that combined changes in fertility and mortality are the leading causes of financial pressure on the OASDI program.

The Social Security population, both covered workers paying into the system and those collecting benefits, is experiencing shifts in age distribution. Decreased fertility rates for generations after the baby boomers (those born between 1946 and 1964) are contributing to an overall older population. In addition, increases in average life expectancy are also contributing to the aging of the U.S. population. The combination of decreasing fertility and longer life expectancies results in higher costs, as presented in Figure 1 , which shows OASDI costs increasing as a percentage of taxable payroll. As costs remain above income, the trust funds' assets are used to fulfill scheduled monthly benefit payments. The Board of Trustees projects this process will continue into 2034, after which the trust funds' assets are exhausted and reserves no longer exist.

The OASDI program can pay scheduled benefits while operating with a cash flow deficit (i.e., costs exceed revenues) during periods of positive trust funds balances because assets held in the trust funds can be redeemed to augment continuing income. However, this process cannot last indefinitely. As shown in Figure 1 , a cash flow deficit is projected to persist throughout the 75-year projection period (2019-2093). This report presents data showing that the projected deficits are the result of rising costs associated with demographic changes, outlines how these demographic changes will impact the OASDI program's ability to fulfill benefit payments, and discusses some options policymakers have to address the program's financial shortfall.

The Social Security Population Is Growing Older

Driven by reduced fertility rates and increasing longevity, the Social Security population is aging. In other words, the percentage of the Social Security population at the older end of the age distribution is increasing. This point is underscored by considering three broad age subgroups: (1) those aged 65 and older ; (2) those aged 20 through 64 ; and (3) those under age 20 . Analyzing the population using these broad age groups highlights the concentration of those likely to be retired or close to retirement (i.e., aged 65 and older), those in ages commonly seen as prime working years (i.e., aged 20 through 64), and those generally considered not yet in the paid workforce (i.e., under age 20).

Table 1 shows population growth rates for the 70-year period from 1945 to 2015, the first and the most recent years, respectively, for which the trustees publish historical data. It also shows the trustees' projections for growth in the population, and its subgroups, for the ensuing 70-year period of 2015 through 2085. From 1945 through 2015, the Social Security population more than doubled.

Table 1 shows that, although the population grew by 120% over this period, growth in major age groups varied. On a percentage-change basis, the largest growth was observed in the 65 and over age group. From 1945 through 2015, this age group grew by 338%, indicating that the number of people in the United States aged 65 and older more than tripled. This demographic trend underscores the degree to which the United States is growing older; in 1945, those 65 and older accounted for 7% of the total population, whereas in 2015, those 65 and older accounted for about 15% of the total population.

This trend has implications for the Social Security program's ability to meet all of its projected scheduled benefits as the younger and slower-growing age groups of working age (i.e., those aged 20 to 64) are paying into the system while the older and faster-growing age groups (i.e., those aged 65 and older) are likely to be collecting benefits. The right-hand column in Table 1 shows that the trustees projected future years will continue to see growth in the 65 and older age group outpace that of the overall population. By 2085, the 65 and older age group is projected to make up about 22% of the total population. As this trend persists, which it is projected to do under the trustees' intermediate assumptions, it will cause OASDI program costs to rise more rapidly than revenues, thereby degrading the program's ability to pay full scheduled benefits.

Table 1 also shows how the working-age population is projected to be a smaller percentage of the overall population. This is an essential consequence of an aging population. That is, as the percentage of those aged 65 and older is increasing, the percentages in the other age group (i.e., working ages between 20 and 64) are decreasing. This point is reinforced by examining dependency ratios.

The changes in the Social Security population's composition can also be expressed as dependency ratios. Dependency ratios indicate a dependent population's burden on the working-age population. Table 1 shows that in 1945, about 59% of the total population was working age, between the ages of 20 and 64. The next-largest age group was the under 20 age group, which accounted for about 33% of the population. In 1945, the United States could be described as youth dependent because the working-age population was supporting the next-larger, under 20 population. The same could be said for the United States in 2015, when the 20 to 64 age group was about 59% of the total population and those in the under 20 age group accounted for 26% of the total population ( Table 1 ). That is, from 1945 to 2015, the United States became less youth dependent. Over this time period, the percentage of the total population aged 65 and older increased from 7% to 15%, indicating that the United States was becoming more aged dependent . The United States is projected to age from a youth-dependent population to an aged-dependent population, where the working-age population will be supporting the next-larger, 65 and older population. The transition to a more aged-dependent population is important for Social Security purposes because the program's ability to continue to pay beneficiaries relies on taxes paid by current workers. As discussed, the dependency ratios have changed over time and are projected to continue to change. Figure 2 presents a more detailed look at the dependency ratios and shows how they have changed in a historical context and how they are projected to change throughout the trustees' 75-year projection period.

Figure 2 shows the youth dependency ratio, which is the ratio of the population under 20 to the population aged 20-64. It is an approximate measure of how many young persons are supported by those in working ages. For instance, in 1945 the youth dependency ratio was 56%, suggesting that every 100 people in working ages were supporting 56 youths. From 1945 to 1965, the youth population increased relative to the working-age population, resulting in an increasing youth dependency ratio. As the baby boom generation attained working ages (the oldest of the baby boom generation turned 20 in 1966), the working-age population increased relative to the youth population and this ratio began to decrease. By 1985, when all of the baby boom generation had reached working age (the youngest of the baby boom generation turned 20 in 1984), this ratio had decreased to 51%, a level comparable to that observed prior to the baby boomers (i.e., in 1945 the youth dependency ratio was 56%).

Figure 2 also shows the aged dependency ratio. The aged dependency ratio is the ratio of the population aged 65 and older to the population aged 20-64. Although the age at which a beneficiary can collect Social Security benefits varies by birth year, this ratio is an approximate indicator of the number of people likely to be collecting benefits relative to those still working. For instance, in 1945 the aged dependency ratio was 12%, suggesting that for every 100 working-age people there were 12 people collecting benefits. The increase in this ratio highlights the aging of the population. As shown, this ratio increased from 12% in 1945 to 25% in 2015. That is, the number of people collecting benefits versus the number of people still working doubled over this period. Throughout the trustees' 75-year projection period, this ratio will continue to increase under the intermediate projections, due in large part to the baby boomers' continued retirement from the work force, relative to the numbers in the working-age population. The trustees project the aged dependency ratio to exceed 35% by 2025 and 40% by 2065. This projected tripling of the aged dependency ratio reflects the aged population's faster growth compared with that of the working-age population.

The total dependency ratio is the ratio of those aged 65 and above and those aged under 20 to those aged 20-64. Thus, the ratio is an approximate measure of the number of people not of working age to the number of working-age people. The beginning of the baby boom generation is indicated by the rising total dependency ratio as shown in Figure 2 . The total dependency ratio remained relatively stable from the mid-1980s to the early 2010s as the baby boomers remained in working ages. The oldest baby boomers reached full retirement age in 2012, making it the first year that a baby boomer could retire with full benefits. Thus, as the baby boom generation began to exit the paid labor force in the 2010s, the ratio can be seen to rise slightly. The ratio is projected to increase as more of that generation enters retirement age.

Owing to the sustained decrease in total fertility rates since the 1970s, the aged dependency and total dependency ratios are projected to increase even after the last baby boomers have reached full retirement age in 2031. The demographic trends that created the baby boomers led to an imbalance between the number of people who have or will retire (i.e., present and potential beneficiaries) and the number of people in working ages (i.e., present and potential covered workers). Specifically, as the baby boom generation ages, those aged 65 and older will make up a larger portion of the total population. The transition from a youth-dependent population to an aged-dependent population means the number of beneficiaries will increase faster than the number of covered workers. As a result, the trustees project that OASDI costs will rise relative to revenues.

The aging of the Social Security population is partially driven by a decline in the total fertility rate after 1965. The total fertility rate (TFR) is the average number of children that would be born to a woman throughout her lifetime if she were to experience, at each age of her life, the birth rate observed in that year. In 1920, the TFR was 3.26 children per woman. By 1940, the TFR was comparatively lower, at a rate of 2.23 children per woman; this was the lowest TFR that had been observed to date. This decrease was reversed within the decade when a period of high fertility created the baby boom generation, those born between 1946 and 1964 ( Appendix A ). This period of high fertility is shown in Figure 3 and is marked on either side by periods of low fertility. In fact, fertility rates after 1964 (i.e., immediately following the baby boomers) decreased to the lowest levels recorded in the United States. Much of what makes the baby boom generation so impactful is that the cohort was both preceded and followed by low fertility rates. Figure 3 shows the historical fertility rates as measured by the National Center for Health Statistics (Centers for Disease Control and Prevention) and the trustees, as well as the trustees' projected fertility rates under their intermediate assumptions.

The U.S. TFR reached a minimum of 1.77 children per woman in 1975. The TFR has remained at relatively low levels in the years that followed, a trend that is projected to continue. The Board of Trustees projects that the TFR will remain close to 2.0 children per woman throughout the 75-year projection period.

Causes for the Decrease in Fertility Rates

Research suggests that there are many contributing factors for the decline in fertility rates. For instance, changes in fertility rates have been closely linked to changes in personal income and changes in the employment rate. This perhaps explains why a decrease in fertility coincided with the 2008-2009 financial crisis, before which the fertility rate was increasing. Additional research reinforces economic and financial uncertainty's effect on fertility and birth rates. Studies have shown that those who worried more frequently about future job prospects were more likely to have doubts about having children and expected to have them later in life. Research has also suggested that a mother's postponement of childbearing increases her children's socioeconomic opportunities.

Costs associated with raising children may have effects as well. From 1960 to 2015, the average cost of raising a single child from birth to age 17 for a middle-income, married couple increased 16% in real terms. Over this period, the portions of costs attributable to housing, food, transportation, and clothing have decreased. However, costs associated with healthcare doubled as a percentage of total cost and costs associated with child care and education increased from 2% of total costs to 16%. To the degree parents contribute to the costs of higher education, the increasing trend in child care costs may be understated.

The decision to have children later in life is reflected in historical data. Specifically, the decline in fertility among women has not been shared uniformly across age groups. In fact, since the mid-1970s fertility among women aged 30-34 and 34-39 has been increasing ( Figure B-1 ). These data suggest that although the desire to have children remains, the age at which it is done has increased. This postponement of childbearing results in a lower overall fertility rate.

Decreasing Mortality and Longer Life Expectancy

On average, the Social Security population is living longer. This demographic trend is observed in two complementary measures: a decreasing mortality rate and increasing life expectancy. More individuals within the Social Security population are surviving to retirement age, and once in retirement they are collecting benefits for a greater number of years than previous generations of beneficiaries. For instance, in 1945, one year before the baby boom began, a male at birth could expect to live on average for 62.9 years. In 1965, one year after the baby boom ended, a male at birth could expect to live 66.8 years on average, an increase of almost 4 years. During that same period, the average life expectancy for a female at birth increased by 5.4 years.

The trustees cite several developments over the past century that contributed to the lower mortality rates, including

access to primary medical care for the general population, discovery and general availability of antibiotics and immunizations, clean water supply and waste removal, and the rapid rate of growth in the general standard of living.

Changes in the leading causes of death support the effectiveness of the developments cited by the trustees. In 1900, the leading cause of death in the United States was infectious diseases, such as influenza or tuberculosis (see Appendix C ). From 1900 to 1940, the decline in infectious disease as a major cause of death was largely attributed to nutritional improvements and public health measures; the subsequent development of medical treatments further reduced infectious disease as a leading cause of death. As deaths due to infectious diseases declined, deaths due to diseases of old age increased. From 1900 to 1940, diseases associated with old ageâcardiovascular disease and cancerâbecame the two leading causes of death. By 1950, cardiovascular disease alone led to more deaths than the next four leading causes. However, owing to improvements in medical treatments and access to those treatments, the age-adjusted death rate for cardiovascular disease decreased by more than 70% by 2015. In addition, this time period overlaps with the 1965 creation of Medicare, which has provided older Americans with better access to health care.

Figure 4 shows how the developments cited by the trustees combined to decrease mortality rates in the Social Security population. From 1945 to 2015, the death rate declined from 1,716.6 persons per 100,000 to 815.8 persons per 100,000, an approximate decline of 52%. This trend underscores the aging of the Social Security population, that is, more and more people covered by Social Security are surviving to retirement age. The trustees project this trend of decreasing mortality rates will continue throughout the projection period. Figure 4 shows historical death rates as measured by the National Center for Health Statistics (Centers for Disease Control and Prevention) and the trustees, and the trustees' projected death rates under their intermediate assumptions.

The decrease in mortality rates from 1945 to 2015 translated into higher average life expectancies for Social Security-covered individuals, both those currently working and those collecting benefits. A main measure of life expectancy is period life expectancy: an individual's expected average remaining life at a selected age, assuming no future changes in death rates.

In 1945, the period life expectancy at birth was 62.9 years for a male and 68.4 years for a female. This indicates that in 1945, shortly after Social Security began regular monthly payments, the average newborn male was not expected to reach full retirement age and the average female was not expected to live more than a few years beyond full retirement age (in 1945 the full retirement age was 65, see Table 2 ). In 2015, the period life expectancy at birth was 76.2 years for a male and 81.0 years for a female. Thus, males and females born in 2015 can expect at birth to live approximately 13 years longer than those born in 1945.

Decreasing age-specific mortality rates at the older ages also translate into longer period life expectancy at age 65, an age commonly associated with retirement. In 1945, shortly after Social Security began regular monthly payments, a 65-year-old female could expect to live another 14.4 years on average and a 65-year-old male could expect to live another 12.6 years. In 2015, those life expectancies were 20.4 years and 17.8 years, respectively. In 2015, more of the population survived to the age at which they were eligible for Social Security benefits than in 1945. In addition, individuals reaching eligibility age in 2015 exhibited longer period life expectancies than in 1945. As shown in Figure 5 , the trustees project this trend to continue throughout the projection period, thereby contributing to the OASDI program's rising costs.

Rising Costs and Program Financial Shortfalls

Population aging has consequences for the Social Security system's financial sustainability. As a result of lower fertility rates and increased life expectancy, in 2035 the Social Security system is projected to experience aged dependency ratios ( Figure 2 ) not observed during the program's history. The aged dependency ratios are projected to trend higher as the baby boom generation retires. In 2018, approximately 10,200 baby boomers per day attained age 65; this figure is expected to reach 11,000 per day by 2029. This demographic trend suggests that the ratio of persons collecting benefitsâor soon to beâto those paying into Social Security will increase. The more this ratio increases, the more strain is placed on the OASDI program's financial position.

An Increasing Number of Beneficiaries per Covered Worker

An alternative measure of OASDI program sustainability is the ratio of beneficiaries per 100 covered workers. For example, a ratio of 30 indicates that for every 30 beneficiaries (i.e., individuals collecting benefits) there are 100 workers in covered employment (i.e., individuals subject to the payroll tax). Increases in this ratio suggest that those in covered employment are supporting an increasing number of people collecting benefits. Figure 6 displays ratios of historical and projected beneficiaries per 100 covered workers.

The ratio of beneficiaries per 100 covered workers through year 2031 will be largely influenced by the baby boom generation. The oldest of the baby boomers turned 20 in 1966 and started to enter the paid labor force, becoming covered employees. From 1970 to 2008, a period in which most baby boomers were working age, the ratio of beneficiaries per 100 covered workers remained around 30. In this period, the ratio never fell below 27 or rose above 31.

From 2009 to 2017, the period in which the oldest of the baby boomers reached full retirement age, the number of beneficiaries per 100 covered workers increased from 31 to 35. The trustees project this ratio to rise steadily, reaching 44 in 2031, the year in which the youngest baby boomers will reach full retirement age. When the youngest baby boomers, those born in 1964, reach 70 years of age in 2035, the ratio of beneficiaries per 100 covered workers is projected to be 46. Previous research suggested that under the current tax rates and benefit schedule, the OASDI program requires a ratio of 35 beneficiaries to 100 covered workers to maintain itself as a pay-as-you-go program.

Rising Costs and the Program's Funding Challenge

The line representing the ratio of beneficiaries per 100 covered workers in Figure 6 corresponds to the OASDI cost as a percentage of taxable payroll line shown in Figure 1 . The trustees state the following:

This similarity emphasizes the extent to which the cost rate [annual cost as a percentage of taxable payroll] is determined by the age distribution of the population. The cost rate is essentially the product of the number of beneficiaries and their average benefit, divided by the product of the number of covered workers and their average taxable earnings.

When these lines are graphed together, this relationship becomes more evident. Figure 7 highlights how the rise in the number of beneficiaries per 100 covered workers closely mirrors that of OASDI annual costs. Both measures remained relatively stable from the 1970s through the 2000s, a period in which a majority of the baby boomers were considered to be of prime working ages. Both measures have increased in the 2010s, and they are projected to continue to do so as the baby boomers transition from prime working ages into retirement.

The effects of aging on the Social Security program are already evident when considering only the Disability Insurance (DI) program. In a 2014 testimony before Congress, the Chief Actuary stated that the effects of aging had already contributed to rising costs in the DI program. As they entered young adulthood, more baby boomers entered the workforce than received disability benefits. This trend reversed as the baby boomers entered the disability-prone ages of 45 to 64. The trend is projected to continue as baby boomers approach retirement. As explained by the Board of Trustees,

From 2019 to 2038, the OASI cost rate [annual cost as a percentage of taxable payroll] rises rapidly because the retirement of the baby-boom generation will continue to increase the number of beneficiaries much faster than the number of workers increases, as subsequent lower-birth-rate generations replace the baby-boom generation at working ages.

Figure 1 graphs OASDI annual costs along with annual income, expressed as a percentage of taxable payroll. Figure 1 shows that costs are rising while incomes are relatively stable and that costs are projected to exceed income for the duration of the projection period. The persistence of this imbalance will strain the OASDI program's long-range financial position.

As a primarily pay-as-you-go program, the OASDI is self-financing. It is funded primarily through a payroll tax on covered earnings up to an annual limit and by federal income taxes paid by some beneficiaries on a portion of their OASDI benefits. In addition, from 1984 through 2009, annual income from tax revenues exceeded annual costs. This resulted in annual cash surpluses that were invested in federal government securities held in the OASDI Trust Funds, where they earned interest, thus providing the system a third income source.

A program with contingency reserves may experience periods of cash deficits, in which annual costs are greater than annual income. With sufficient reserves, such a program need not operate as a strict pay-as-you-go program. However, a pay-as-you-go program cannot operate with indefinite annual cash deficits. As shown in Figure 1 , annual costs are projected to exceed annual income throughout the 75-year projection period. Although the OASDI program can draw upon assets in the trust funds to fulfill scheduled payments temporarily, the program cannot do so indefinitely. The trustees project there to be sufficient trust funds reserves to augment tax revenues and pay all scheduled benefits through 2034. The trustees estimate that trust funds reserves will be exhausted sometime in 2035. Once the trust funds are exhausted, the program must operate as a strict pay-as-you-go system, meaning it will only be able to pay out in benefits what it receives in revenues. At the point of OASDI Trust Funds depletion, program revenues will provide the OASDI program funding to pay only 80% of scheduled benefits.

Demographically Driven Policy Options to Address the Financial Shortfall

Policy measures seeking to improve trust funds solvency can generally be categorized as reducing benefits or increasing revenues. For illustrative purposes, the trustees estimate changes to the current payroll tax rates and benefit schedule that would maintain trust funds solvency throughout the 75-year projection period. To give a sense of the funding shortfall's magnitude, if measures to maintain trust funds solvency were enacted in 2019, they would require a permanent increase in the payroll tax from its current rate of 12.40% to 15.10%, or a reduction in scheduled benefits of 17% for all current and future beneficiaries, or a combination of both. The increasing costs associated with the OASDI program indicate that more substantial measures are necessary as time elapses. If similar policies were enacted in 2035, the projected year of trust funds depletion, the permanent payroll tax rate needed to restore solvency would increase to 16.05%. Similarly, the necessary permanent reduction of scheduled benefits would increase to 23%. Lawmakers have a wide range of policy options at their disposal to address the projected funding shortfall. This section highlights several policy options that address the funding shortfall's demographic drivers.

Extend Social Security Benefits for Childcare

As discussed, research suggests that economic and financial uncertainty may be a large driver behind many people's decision to postpone childbearing, thus reducing fertility. Social Security is designed as a social insurance program that protects workers and their families against a loss in earnings due to old age, disability, and death. Understanding the large financial burden that childbearing requires, some proposals argue for Social Security benefits to be extended to cover childcare in times of birth or adoption. While not specifically intended to increase fertility, these proposals recognize the hardships that accompany childbearing and aim to reduce financial pressures around that decision. By seeking to reduce one of the larger impediments to fertilityâfinancial stressâsuch proposals could result in increased fertility.

Incorporate Childcare in the Social Security Benefit Formula

The Social Security benefit formula is used to compute a worker's Primary Insurance Amount (PIA), which is the worker's basic monthly benefit amount payable at the full retirement age. To compute the PIA, the formula first indexes a worker's lifetime covered earnings to reflect changes in national wage levels, as measured by the Social Security Administration's average wage index (AWI). The indexing process ensures a worker's or family member's benefit will reflect increases in average wage growth observed over the worker's earning history. After indexing, the highest 35 years of earnings are summed, and the total is divided by 420 (the number of months in 35 years) to determine a worker's average indexed monthly earnings (AIME). Brackets of a worker's AIME are replaced at different rates, the sum of which is the PIA.

Exiting the paid workforce to have children can impact a worker's future Social Security benefit. For instance, if a worker has fewer than 35 years of covered earnings, years of zero earnings are entered in the calculation. That is, if a worker forgoes covered earnings to have children, the worker's earnings record will reflect no income for that time. Recognizing the benefit formula's adverse effect for years of no earnings due to childcare, some proposals would reduce the number of computation years used in the benefit formula. Such a proposal would allow one parent per household to claim dropout years for years in which that parent had no earnings and provided care for a child under 6 years of age. For example, the benefit formula for a parent with no earnings for two years due to childcare would use the highest 33 years of earnings in the calculation.

Childcare credits are another option that would incorporate childcare into the Social Security benefit formula. Proponents of this method argue that childcare is essentially unpaid work and seek to ensure parents with young children are credited for their caregiving. Under such a proposal, wage credits would be set at one-half the average wage index for that year (e.g., one-half of the AWI for 2018 is $25,947). Parents earning less than the childcare credit level would have their earnings records increased to that level. Parents earning more than the childcare credit level would not receive any credit.

The effects of policy changes that may result in increased fertility are uncertain. As shown in Figure 3 , the projected fertility rate is expected to be stable around 2 children per woman. Under current law and the trustees' intermediate assumptions, each increase of 0.1 in the fertility rate decreases the projected funding shortfall by about 7.6%. This suggests a 65% increase in childbearing (i.e., to approximately 3.3 children per woman) would be needed, absent other changes, to avoid trust fund depletion.

Some policymakers have proposed increasing the eligibility ages to address changing demographics and their effects on the OASDI program's solvency. For instance, a policy measure that increases the full retirement age (FRA) would be categorized as a provision that reduces benefits, as beneficiaries would then collect benefits for a shorter duration of time or accept a higher actuarial reduction in their monthly benefits by claiming at the age they originally intended.

Previous Congresses have addressed increasing the FRA. Facing a funding shortfall, Congress gradually raised the FRA, from age 65 to age 67, as part of the Social Security Amendments of 1983 ( P.L. 98-21 ). Increasing the earliest eligibility age (EEA), a benefit-reducing mechanism, was one of many measures included in this legislation that sought to address previous solvency issues. The Social Security Amendments of 1983 also enacted measures that increased revenues, including provisions that increased the payroll tax and made a portion of Social Security benefits themselves subject to taxation.

Table 2 shows the gradual increase in the FRA depending on year of birth.

The Social Security program is once again facing projected long-range funding shortfalls. Similar to 1983, a common proposal is to increase the EEA or to further increase the FRA. On one hand, some argue that the average increases in life expectancies indicate that people work until older ages, and thus collect benefits at an older age. On the other hand, those opposed to raising the FRA argue that increases in average life expectancies are not shared equally among covered workers.

The SSA's Office of the Chief Actuary (OCACT) publishes estimates for policy provisions that affect claiming ages and are routinely included in legislative proposals. These policy options include provisions that would affect the FRA and provisions that would affect both the FRA and the EEA. Each provision's efficacy can be assessed by its effect on the projected solvency date and its reduction in the long-range actuarial balance , shown for each option in its respective table. For illustrative purposes, a provision that would gradually increase the full retirement age to 68 is estimated to improve the long-range actuarial balance by 16% (compared to current law) and extend solvency to 2035, one year later than under current law.

OCACT projects none of the numerous policy provisions raising eligibility ages to result in trust funds solvency throughout the projection period or to completely eliminate the long-range funding shortfall. A 2015 CBO report found similar results in its analysis of four policy measures: (1) an increase in the FRA of one year; (2) an increase in the FRA of three years; (3) an increase in the FRA by one month per birth year; and (4) an increase in the FRA and EEA by one month per birth year. CBO's findings largely mirror OCACT's in showing that an increase in either one or both of the FRA and EEA reduces Social Security program costs. However, a policy measure adjusting only the age at which benefits could be claimed would not be sufficient to offset the funding shortfall. This outcome suggests that policy measures only addressing demographic changes via eligibility ages are limited in their ability to resolve the effects of rising OASDI program costs.

Research suggests that raising the FRA or EEA would negatively affect certain segments of the population. Although average life expectancy in the United States is increasing, the increases are not equally shared among the population. For instance, women have a longer life expectancy than men and whites have a longer life expectancy than blacks. Life expectancy is also stratified by income level. Numerous studies show that life expectancy is positively related to income and that the gap itselfâthe difference in life expectancies between high earners and low earnersâis also increasing. Social Security benefits are based on the overall population's average life expectancies, suggesting that groups with longer average life expectancies (e.g., higher-income individuals) will collect more lifetime benefits than groups with shorter average life expectancies (e.g., lower-income individuals). Any provision to increase claiming ages may very well exacerbate this difference in lifetime benefits.

A method of increasing the FRA could be to index the FRA for changes in life expectancies. One possible approach would be to index the FRA to maintain a constant ratio of expected retirement years (i.e., life expectancy at FRA) to potential work years (i.e., FRA less 20 years). Another policy option would be to simply adjust the FRA so as to hold the number of expected retirement years constant based on projected life expectancies. As discussed above, life expectancies across different segments of the population can differ by factors such as gender, race, and income. In pursuing options involving indexing the FRA, policymakers would need to address differences in projected life expectancies.

Policy options that would index the FRA can be categorized as cost-reduction measures, because they would decrease total benefits as a means to account for longer life expectancies. Although both options discussed above would reduce the projected funding shortfall, neither would eliminate it completely. Similar to options that may address fertility or a straightforward increase in the FRA, the projected effects of indexing the FRA for changes in life expectancies alone would not eliminate the projected funding shortfall.

A range of policy options exists that would address the increases in longevity by encouraging delayed claiming. One such option would be to increase the number of years used in the benefit formula. For instance, under current law, the benefit formula uses a worker's highest 35 years of earnings to compute the primary insurance amount (PIA). Including more years of earnings in the benefit formula (e.g., 40 years) would likely include years of low earnings from the start of a worker's earning history or years of no earnings. Under such a policy, a worker could choose to work for more years (i.e., to replace years of low earnings with years of high earnings) or take advantage of delayed retirement credits to attain a PIA that would have been earned had the benefit formula not changed. That is, to maintain the benefit scheduled under current law a person would need to work longer, delay claiming, or a combination of both.

Under current law, workers can receive their full PIA once they reach FRA. However, a worker can elect to delay payment of benefits and, in doing so, collect delayed retirement credits. For those born in 1960 and later, a credit is worth 8% of a worker's PIA for each year of delayed claiming. For instance, a worker born in 1960 who reaches FRA at 67 is entitled to 100% of his or her PIA. That same worker could collect 124% of his or her PIA if claiming is delayed three years (at age 70). Any reduction in the benefit formula that would result in a decrease of benefits would then require some use of delayed claiming so as to collect the same PIA as under current law.

A provision that would incentivize workers to delay claiming, perhaps through an increase in the number of computation years, could have a negative earnings impact on some workers. For instance, such a provision would favor those earning at high levels later in their careers (so as to replace years of low earnings with years of higher earnings). In addition to possibly favoring higher earners, such a provision could adversely affect certain types of labor. That is, such a policy proposal would essentially favor those who could still work. Workers with careers in more arduous work who were unable to continue working beyond the current FRA would receive a lower PIA under such a proposal.

On average, increases in life expectancy have allowed current Social Security beneficiaries to collect benefits for a longer period of time. However, the increase in life expectancies, when paired with low fertility rates, will negatively impact the program's long-range financial position and weaken its ability to pay all scheduled benefits as projected under current law. These demographic trendsâincreasing life expectancy and decreasing fertilityâhave resulted in an aging Social Security population. As the baby boom generation retires, the ratio of beneficiaries relative to people in covered employment will grow. As this ratio rises, Social Security costs rise as well. The rising ratio of beneficiaries to covered workers can exist so long as trust funds assets remain to supplement the program's annual tax revenues. Rising costs are projected to deplete trust funds reserves in 2035. After such time, Social Security program revenues will no longer be sufficient to pay full benefits. Under current law, the Social Security program's sustainability, and its ability to pay full benefits, is largely a demographic issue. Policy measures aimed at addressing the changing demographics, specifically those increasing retirement ages to reflect increasing life expectancy, improve the program's solvency and long-range financial status. Such policy measures are estimated to reduce program costs. However, the reduction in benefits implied by such measures would not be evenly distributed across all segments of the population. In addition, increasing eligibility ages (i.e., reducing costs) alone is not projected to restore solvency throughout the projection period. Given the magnitude of the OASDI program's projected long-range funding shortfall, policy measures that include both a revenue-increasing and a benefit-reducing mechanism to restore solvency increase the likelihood that full benefits will be maintained.

Appendix A. The Baby Boomers in the United States

The first baby boomers were born in 1946; the last baby boomers were born in 1964. The period of 1946-1964 is marked on either side by low birth rates. As a result of the low fertility rates that followed the baby boomers, they are being replaced in the workforce by cohorts resulting from lower fertility rates.

The baby boom's births spanned nearly two decades, denoted with I in Figure A-1 . The older baby boomers started to enter the workforce as the youngest were just being born (II in the figure below). Time period III denotes the stage at which all baby boomers are at least 20 years of age, an age commonly associated with working age. In period IV, baby boomers are attaining full retirement age and beginning to exit the workforce. In period V, all baby boomers are eligible for retirement with full benefits.

In 1945, a year before the first baby boomer was born, 7.3% of the Social Security population was aged 65 or older. In 2035, after all baby boomers are eligible for Social Security, 20.5% of the population will be aged 65 or older.

The demographic forces that created an aging population evolved over decades. This is important to policymakers because demographic trends in the Social Security population are contributing to rising costs. These demographic trends result in an imbalance between costs and revenues and are projected to continue beyond the baby-boom generation. This imbalance can also be thought of as a persistent imbalance between those in covered employment and those collecting benefits.