One of the advantages for employees in a group health plan is the contribution most employers make toward the cost of the health coverage premium â in many cases, employers pay one-half or more of the monthly premium for an employee.
The basic format consists of five decimal numerical digits. An extended ZIP+4 code, introduced in 1983, includes the five digits of the ZIP code, a hyphen, and four additional digits that determine a more specific location within a given ZIP code. The USPS provides a free online lookup tool for ZIP codes.
Rating Newest Oldest. Best Answer: Those last four digits are like a ZIP code within a Zip code. In 1983 the U.S. Postal Service began using the expanded ZIP (Zone Improvement Plan) code in order to expedite shipping to specific office blocks, mailing centers, and other areas that receive a high volume of mail. The last four numbers aren't mandatory, but they can help expedite delivery.