FSA and HSA Together: What Blocks Eligibility

A general-purpose health FSA blocks HSA contributions for every month it can reimburse your medical expenses. A spouse’s general-purpose FSA counts as much as your own. A limited-purpose or post-deductible health FSA leaves eligibility intact.

The FSA deadline calculator asks which kind of account you have, and the HSA contribution calculator works month by month, because eligibility is tested on the first day of each month rather than across the year.

The rule in one sentence

Publication 969 states it under “Other employee health plans”: “An employee covered by an HDHP and a health FSA or an HRA that pays or reimburses qualified medical expenses can’t generally make contributions to an HSA.”

The operative words are pays or reimburses qualified medical expenses. An arrangement that can pay a routine doctor’s bill is other health coverage, and other health coverage is what disqualifies you. Publication 969 puts the general form of that rule first: “If you (and your spouse, if you have family coverage) have HDHP coverage, you can’t generally have any other health coverage.”

The three designs that keep eligibility

Publication 969 names the arrangements you can hold alongside an HDHP and still contribute:

Arrangement	Why it does not disqualify you
Limited-purpose health FSA	It pays only dental, vision and similar excepted items, plus preventive care
Post-deductible health FSA	It “doesn’t pay or reimburse any medical expenses incurred before the minimum annual deductible amount is met”
Suspended or retiree-only HRA	Reimbursement is switched off, or begins only after retirement

The publication describes the first two precisely. A limited-purpose FSA or HRA “can pay or reimburse the items listed earlier under Other health coverage except long-term care”, and “can pay or reimburse preventive care expenses because they can be paid without having to satisfy the deductible.”

A limited-purpose FSA is still a health FSA for section 125 purposes, so the same salary-reduction limit applies: $3,400¹ for a plan year beginning in 2026.

A spouse’s FSA counts

The rule is about coverage, not about whose employer pays for it. Publication 969 lists whose expenses a health FSA may reimburse, and the list begins with “you and your spouse”. A general-purpose health FSA held by your spouse can therefore reimburse your medical expenses, which is exactly the coverage the HSA rule disqualifies.

That is separate from the family-limit question, which the HSA rules for married couples work through. One spouse can hold a general-purpose FSA and the other an HSA only where the FSA is built so that it cannot reimburse the HSA holder’s expenses.

The grace period extends the block

A grace period keeps general-purpose coverage running into the following plan year. Publication 969 states the one condition that avoids the consequence: “Coverage during a grace period by a general purpose health FSA is allowed if the balance in the health FSA at the end of its prior-year plan is zero.”

A December 31 plan year with a full grace period therefore runs general-purpose coverage to the middle of March, since the maximum is 2½ months — the 15th day of the 3rd month after the plan year ends². A zero balance on the last day of the plan year is what switches that off.

Publication 969 addresses the grace period expressly. It does not address what a carryover of unused general-purpose health FSA amounts does to HSA eligibility, and Notice 2013-71 does not mention HSAs at all. Confirm that case with your plan administrator or a tax professional rather than reading it off this page.

Losing eligibility mid-year costs you a share of the limit

The 2026 limits are $4,400³ for self-only coverage and $8,750⁴ for family coverage. Each month you are ineligible removes one twelfth of the applicable figure, which is what the HSA calculator computes from the months you mark.

Timing an FSA election and an HDHP enrollment into the same month is the usual source of the problem, because a general-purpose FSA that runs to December 31 blocks the HSA for that whole plan year.

Can I have an FSA and an HSA at the same time?

Not if the FSA is a general-purpose health FSA. Publication 969 states that an employee covered by an HDHP and a health FSA “that pays or reimburses qualified medical expenses can’t generally make contributions to an HSA”; a limited-purpose or post-deductible FSA is the exception.

Does my spouse’s health FSA block my HSA?

Yes, where that FSA can reimburse your medical expenses. Publication 969 lists a spouse among the people whose expenses a health FSA reimburses, and a health FSA that can pay your expenses is disqualifying coverage for you.

What is a limited-purpose FSA?

A health FSA restricted to the items you may hold alongside an HDHP — dental and vision care and similar excepted benefits — plus preventive care. Publication 969 lists it first among the arrangements that leave HSA eligibility intact.

Does an FSA grace period block HSA contributions?

Yes, unless the balance was zero. Publication 969 permits coverage during a general-purpose grace period “if the balance in the health FSA at the end of its prior-year plan is zero”, and the grace period itself can run up to 2½ months — the 15th day of the 3rd month after the plan year ends².

Can I switch to a limited-purpose FSA mid-year?

Election changes are governed by your cafeteria plan document and the change-in-status rules, not by the HSA rules. What the HSA rules fix is the consequence: eligibility is tested on the first day of each month while general-purpose coverage exists.

How much can I contribute if my FSA ends partway through the year?

One twelfth of the annual limit for each month you are an eligible individual on the first day. For 2026 the annual figures are $4,400³ and $8,750⁴, and the HSA calculator applies the monthly split.