Slott Report: HSA contributions fall to self-only limit when one spouse enrolls in Medicare

Once one spouse enrolls in Medicare, the other spouse can fund an HSA only at the self-only limit, and the Medicare-enrolled spouse cannot contribute, according to the Slott Report Mailbag. The answer, published Thursday, addressed a reader whose spouse is on Medicare while the other remains covered by a high-deductible health plan.

For 2026 the self-only HSA contribution limit is $4,500, plus a $1,000 catch-up for savers 55 and older. Family contribution limits are aggregated across spouses, but the accounts are not: each spouse opens their own.

A couple that has been funding at the family level loses the older spouse's eligibility at the point Medicare enrollment begins, and what remains is the younger spouse's self-only figure rather than a shared one.

The mailbag's second question came from a 71-year-old holding a small traditional IRA at Vanguard and larger traditional and Roth IRAs at Fidelity. He wants to move the Vanguard account into the Fidelity traditional IRA, convert part of that IRA into the Fidelity Roth, and know whether both fit in one year and whether the order matters.

Both transactions can happen this year, and the order does not matter, per the mailbag. For the consolidation it recommends a direct transfer rather than a 60-day rollover, which avoids tax reporting, the 60-day deadline and the once-per-year rollover rule. On the conversion, the mailbag's answer is that a partial Roth conversion can be done at any time and for any amount.

The rule that applies later is sequencing around required minimum distributions: once RMDs begin, the full RMD must come out before any Roth conversion. That constraint is not yet live for this reader, who describes his RMDs as a couple of years away, so this year's conversion can be sized around the tax picture rather than around a distribution.