Monthly eligibility model

HSA contribution limit calculator

Start with the annual IRS limit, then account for the months and coverage that actually qualify.

$0
Maximum contribution from all sources
Eligible months
Ordinary prorated limit
Remaining contribution room
Projected excess
Potential recurring 6% tax
Calculation scopeFederal HSA limit

How this calculator treats the limit

Eligibility is measured on the first day of each month. The ordinary limit adds one-twelfth of the applicable annual self-only or family limit for every eligible month, plus a prorated age-55 catch-up when selected. Employer and employee contributions are combined.

Last-month rule warning: using a full-year limit from December 1 eligibility creates a testing period through December 31 of the following year. The result labels that condition rather than hiding it.