To be able to contribute to an HSA after age 65, you must not enroll in Medicare Part A or Medicare Part B. HSA rules make a distinction between being merely “eligible” for Medicare (keep HSA eligibility) and being “entitled” to or “enrolled” in Medicare (lose HSA eligibility). You become enrolled in Medicare under Part A by filing an application or being approved automatically. The Social Security Administration automatically “enrolls” you in Medicare Part A when you begin collecting Social Security benefits. Accordingly, if you are receiving Social Security payments and are over 65, you are almost certainly enrolled in Medicare Part A. Also, employees that work for smaller employers (fewer than 20 employees) will have Medicare as their primary insurance at age 65. Some people; however, avoid enrolling in Medicare and being automatically enrolled by waiting to receive Social Security. If you are not enrolled in Medicare and are otherwise HSA eligible, you can continue to contribute to an HSA after age 65. You are also allowed to contribute the $1,000 catch-up.