For 2015, health savings account contribution limits are $3,350 for individual coverage and $6,650 for family coverage, according to Optum Bank. These limits are set by the Internal Revenue Service each year and include both employee and employer contributions, according to the Society for Human Resource Management. For eligible individuals who are 55 or older when the tax year ends, the limit increases by $1,000.
Contributions for the previous year are allowed until the tax filing deadline for that year, which is generally April 15 of the following year, according to Optum Bank. Contributions that exceed the allowed maximum must be counted as taxable income and are taxed at 6 percent. HSA rules also allow catch-up contributions at a maximum of $1,000 per year, according to the SHRM.
An individual who turns age 55 by Dec. 1, 2015, with self-only coverage can contribute up to $4,350 in 2015. However, beginning the first month an individual enrolls in Medicare, the contribution limit is zero, notes the IRS. For example, if an individual with self-only HDHP coverage who is eligible for an additional contribution of $1,000 turns age 65 in July 2015 and enrolls in Medicare, the individual's 2015 contribution limit is $2,175, or $4,350 times 6, divided by 12.