Retirement Lock and Prescription Drug Insurance: Evidence from Medicare Part D

I examine whether lack of an individual market for prescription drug insurance causes individuals to delay retirement. Exploiting the 2006 introduction of Medicare Part D, which subsidized drug insurance for Americans over age 65, I use a triple-differences design that compares labor outcomes of individuals with retiree health insurance up to age 65 to those with insurance for life, before and after age 65, before and after 2006. I find that those with benefits only to age 65 decreased full-time work by 8.4 percentage points, of which 70 percent was due to transitions to part-time work.