Facebook Urges Members to Add Organ Donor Status Nearly 7,000 people in the United States die each year while waiting for an organ transplant. It is a number that Facebook hopes to lower with its vast network of 161 million members in this country. The company announced a plan on Tuesday morning to encourage everyone on Facebook to start advertising their donor status on their pages, along with their birth dates and schools - a move that it hopes will create peer pressure to nudge more people to add their names to the rolls of registered organ donors. It is a rare foray by Facebook into social engineering from social networking, and one with a potentially profound effect, according to experts in the field of organ donation. They say people declaring on Facebook that they are organ donors could spur others to sign up at motor vehicle departments or online registries. But these experts say Facebook could create an informal alternative to such registries that could, even though it carries less legal weight, lead to more organ donations. That is because a disclosure on Facebook could provide the evidence of consent that family members need when deciding whether to donate the organs of a loved one, said Dr. Andrew M. Cameron, the surgical director of liver transplantation at Johns Hopkins Hospital. "This is going to be an historic day in transplant," said Dr. Cameron, adding that people who die for want of an organ do so mostly because there are not enough organ donors, not because of any shortcomings in medical technology. The math will radically change, and we may well eliminate the problem. Dr. Cameron estimated that millions of people could shift their donation status overnight. Previous efforts to encourage organ donation have struggled, Dr. Cameron said, because the issue is sensitive and personal and because the decision is made at the motor vehicle department, where many people may not want to focus on the prospect of dying. Fewer than half of adult Americans have signed up to be an organ donor. "We have attempted to have a sensitive conversation, one that addresses your mortality, at the D.M.V.," Dr. Cameron said. Now we move the conversation into your own home or office with 120 of your closest friends on Facebook. Under the Facebook plan, members will be able to declare and update their organ donation status. The status will appear with other biographical information in a section called Health and Wellness, which includes, for example, updates on whether a person has recently lost weight or ever broken a bone. This feature will also lead to links to state online donor registries, where people can change their donor status; or they can still do so the traditional way, by visiting the local motor vehicle department. Facebook is introducing the change not only in the United States but also in the United Kingdom, where it has around 30 million members. The company says it plans to add it in several other countries in the coming months. Globally, Facebook has about 900 million members. "We never could have anticipated that what started as a small network would evolve into such a powerful tool for communication and problem solving," said Mark Zuckerberg, the founder and chief executive of Facebook, and Sheryl Sandberg, the chief operating officer, in a statement. As this happens, we hope to build tools that help people transform the way we all solve worldwide social problems. Some experts in the field of organ donation agreed that Facebook could substantially help to change the culture, but they emphasized that the Web site would not become a de facto registry. Charlene R. Zettel, chief executive of Donate Life California, an arm of a national advocacy group that promotes organ donation, noted that when someone signs up with an official state registry, it is a legal declaration that allows their organs to be donated without family consultation. In a situation where the deceased is not in a registry, organ procurement specialists often contact the family to persuade them to grant consent and often are able to do so. If people were to declare themselves organ donors on Facebook, Ms. Zettel said, it might simplify and hasten the decision for families to approve a donation.