I become eligible for Medicare in November. I’m currently covered by a high-deductible health plan. Can I make a full-year contribution to a health savings account (HSA)?

Once you are enrolled in Medicare, you are no longer eligible to contribute to an HSA. Your contributions must be prorated for the period in which you have a high-deductible health plan (HDHP). Thus, if you have an HDHP for 10 months, you can contribute 10/12ths of the annual contribution limit for your filing status. For example, if you are single, your contribution limit for 2014 would be $3,583 (10/12ths of the basic limit of $3,300 plus $1,000 for those 55 and older).