When should HSA contributions stop?
Estimate the first month Part A may reach backward and the month before it when HSA eligibility may end.
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Last estimated HSA-eligible contribution month
Potential Part A effective month
Estimated retroactive period
RuleUp to 6 months, never before eligibility
Why two dates are required
Premium-free Part A can be retroactive for up to six months from a late application, but it cannot begin before the first month of Medicare eligibility. This calculator takes the later of those two boundaries and reports the prior month as the last potential HSA contribution month.
Confirm the actual effective date. Social Security and Medicare enrollment facts can differ. Use the effective date on the enrollment record before finalizing or correcting contributions.