The percentage of retirees who return to the workforce varies depending on the specific study, but it can be significant. For example, according to a 2020 survey by the Transamerica Center for Retirement Studies, approximately 57% of American workers expect to continue working in some capacity after they retire. Another survey conducted by the Federal Reserve in 2018 found that 29% of retirees had worked at some point during their retirement, and of those, 50% worked part-time and 50% worked full-time.

Retirees return to the workforce for a variety of reasons, including financial, social, and personal fulfillment.

1. Financial reasons: Some retirees return to work because they need additional income to support their lifestyle or to help them manage unexpected expenses such as medical bills or home repairs.
2. Social reasons: Work can provide social connections, a sense of purpose, and a way to stay engaged with the world around them. Retirees may miss the social interaction and sense of community that comes with working.
3. Personal fulfillment: Some retirees may find that they miss the challenge, structure, and sense of accomplishment that comes with work. They may also have new goals or interests that they want to pursue, and returning to work can help them achieve these goals.
4. Health benefits: Some retirees may find that working part-time can provide health benefits, such as increased physical activity and mental stimulation.
5. Philanthropic reasons: Retirees may want to give back to their community or pursue a passion project that has a charitable or social purpose.

Retirement need not mean the end of meaningful work. On the contrary, retirees return to work for a variety of reasons, and often find success and fulfillment in an entirely new endeavor.