
For plans with coverage effective Jan 1, 2011:
Individuals who are eligible individuals on the first day of the last month of the taxable year (December for most taxpayers) are allowed the full annual contribution (plus catch up contribution, if 55 or older by year end), regardless of the number of months the individual was an eligible individual in the year. For individuals who are no longer eligible individuals on that date, both the HSA contribution and catch up contribution apply pro rata based on the number of months of the year a taxpayer is an eligible individual.