If, for whatever reason, you are enrolled in an HSA- qualified HDHP for a partial year, the maximum HSA contribution for that year must be pro-rated; meaning they must be in proportion to the number of months you were covered by the HDHP.
If you have qualified HDHP coverage on December 1 and maintain qualified HDHP coverage through December of the following year, you have the option to make up to a full year’s contribution instead of pro-rated contributions.
Examples for Calculating Pro-Rated Maximum Contributions
- Bob is younger than age 55. He was covered by an individual HDHP for six months before losing his coverage. What’s the maximum amount he can contribute to his HSA that year? In 2017, the maximum contribution for individual coverage is $3,400. Because Bob was covered by a HDHP for six months (half) of the year, he can contribute half of the maximum amount allowed of $1,700 ($3,400 ÷ 12 months x 6 months = $1,700).
- Lynn, age 58, was covered by a family HDHP for five full months of the calendar year. In 2017, the maximum contribution for family coverage is $6,750, plus an annual catch-up contribution of $1,000 for each spouse over age 55. Because Lynn was covered for five months, she can contribute 5/12 of $7,750 or $3,229 ($7,750 ÷ 12 months x 5 months = $3,229).