HSA Eligibility

The plain answer

You can contribute to an HSA only for months when you are HSA-eligible. In general, that means you are covered by a qualifying high-deductible health plan, have no disqualifying additional health coverage, are not enrolled in Medicare, and cannot be claimed as someone else’s tax dependent.

For 2026, an HSA-qualified HDHP must meet these federal limits:

Coverage	Minimum deductible	Maximum out-of-pocket cost
Self-only	$1,700	$8,500
Family	$3,400	$17,000

How it actually works

The deductible and out-of-pocket limits are necessary, but a plan is not HSA-qualified based on those numbers alone. Except for permitted preventive care and limited exceptions, the plan generally cannot pay benefits before you meet its deductible. Confirm that the plan is labeled HSA-eligible rather than relying on the phrase “high deductible.”

Eligibility is determined month by month, generally on the first day of each month. Coverage under a general-purpose health flexible spending account or health reimbursement arrangement can disqualify you, including some coverage through a spouse. Dental, vision, accident, disability, and certain other limited coverage usually do not.

You may keep and spend an existing HSA after losing eligibility. Losing eligibility stops new contributions for the affected months; it does not take away the account or make qualified withdrawals taxable.

The last-month rule may let an eligible person use the full-year contribution limit when eligible on December 1. It comes with a testing period that generally runs through the end of the following year. Losing eligibility during that period can make part of the contribution taxable and subject to an additional tax.

What this means for you

Check eligibility before setting a contribution amount, then revisit it after a job change, insurance change, Medicare enrollment, marriage, or enrollment in another health benefit. Ask the insurer or employer benefits team to confirm in writing that the plan is HSA-qualified.

For 2026, the maximum contribution is $4,400 for self-only coverage and $8,750 for family coverage. These are annual ceilings, not automatic entitlements. Your allowed amount can be lower when you qualify for only part of the year, and employer contributions count toward the same limit.

Common mistakes

• Assuming every high-deductible plan is HSA-qualified.
• Contributing after Medicare coverage begins. Retroactive Medicare coverage can also affect prior months.
• Overlooking a spouse’s general-purpose health FSA that covers you.
• Using the full annual limit after a midyear eligibility change without checking the monthly calculation or last-month rule.
• Confusing ownership with contribution eligibility. The HSA remains yours even when you cannot add new money.

Related pages

• What Is an HSA?
• Why HSAs Are So Tax-Efficient