Am I Eligible for an HSA? The 2026 Rules

You are HSA-eligible on the first day of a month if all four are true: you have qualifying HDHP coverage, you have no other disqualifying health coverage, you are not enrolled in Medicare, and you are not claimed as a dependent. Miss any one and you cannot contribute for that month. For 2026, a qualifying High Deductible Health Plan must have a minimum deductible of $1,650 (self-only) or $3,300 (family) and an out-of-pocket maximum no higher than $8,300 (self-only) or $16,600 (family) per IRS Rev. Proc. 2025-19.

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Key Takeaways

• Four tests, all required. HDHP coverage, no other coverage, no Medicare, no dependent status.
• HDHP thresholds are IRS-set. 2026: $1,650 / $3,300 minimum deductible, $8,300 / $16,600 out-of-pocket max.
• FSAs are the most common silent disqualifier. A general-purpose FSA -- yours or your spouse's -- zeroes your HSA limit.
• Medicare Part A is automatic at 65 if you take Social Security and ends new HSA contributions immediately.
• Eligibility is measured per month. The limit is prorated to eligible months unless you use the last-month rule.
• The last-month rule lets you contribute the full year if you are eligible on December 1 -- but you must stay eligible for a 13-month testing period.

HSA eligibility is defined by Internal Revenue Code Section 223(c)(1) and is tested on a month-by-month basis. You are an "eligible individual" for a given month only if, on the first day of that month, you satisfy every condition below. Lose any one and that month is out -- but you can re-qualify the next month if you fix it.

1. You are covered by a qualifying HDHP. Section 3 covers the 2026 thresholds.
2. You have no other disqualifying health coverage. Section 5 covers what counts as disqualifying.
3. You are not enrolled in Medicare -- any part. Section 4 covers the Medicare trap.
4. You are not claimed as a dependent on someone else's tax return for the year.

If all four are true on April 1, for example, then April is an HSA-eligible month and you can contribute 1/12 of the annual limit for that month. If you fail any test on May 1, May is not eligible and you must not over-contribute for it. This per-month rule is why partial-year situations require careful proration -- covered in Section 7.

An HDHP is not just any plan with a high deductible. The IRS sets specific dollar thresholds each year under Rev. Proc. 2025-19. To qualify a plan for HSA contributions in 2026, the plan must meet both the minimum deductible and the out-of-pocket maximum.

Source: IRS Rev. Proc. 2025-19. The out-of-pocket cap includes deductibles, copayments, and coinsurance -- but excludes premiums. A plan with a $1,500 deductible does not qualify even though it sounds high, and a plan with a $17,000 family out-of-pocket maximum does not qualify either.

Two more practical points most plan-shoppers miss:

• Preventive care can be covered before the deductible. The HDHP rules explicitly allow zero-cost preventive care (annual physicals, vaccinations, screenings) without breaking HDHP status. Your plan does not have to make you pay full freight for a flu shot to be HSA-eligible.
• "Embedded" family deductibles are tricky. Some family HDHPs apply a lower deductible to each individual within the family. For the plan to remain HSA-eligible, the embedded individual deductible must be at least $3,300 for 2026 -- the family minimum, not the self-only minimum. Ask your insurer or HR for written confirmation.

Your benefits summary or summary plan description should state explicitly whether the plan is "HSA-qualified" or "HSA-eligible." If it is silent, ask before you contribute.

Enrollment in any part of Medicare -- Part A, Part B, Part C (Medicare Advantage), or Part D -- ends your HSA contribution eligibility. You can still spend your existing HSA balance on qualified medical expenses tax-free for life, but new contributions stop the month Medicare coverage begins.

The trap most people walk into:

• Medicare Part A is automatic if you take Social Security. Applying for Social Security at or after age 65 enrolls you in Part A whether you want it or not.
• Part A enrollment can be retroactive up to six months. If you delay Social Security to age 67 and finally enroll, Part A may back-date six months -- which retroactively disqualifies any HSA contributions made during those months.
• You cannot "opt out" of Part A while collecting Social Security benefits. The only way to refuse Part A is to also withhold or repay Social Security benefits.

If you want to keep contributing to an HSA past 65, the clean strategy is to delay both Medicare and Social Security while staying on an HDHP. Stop HSA contributions in the month any Medicare enrollment becomes effective, then make sure the Social Security claim filing date is set after the last month you want to contribute.

The most underestimated test is the "no other health coverage" requirement. The rule: you cannot be covered by any non-HDHP health plan that pays for medical expenses before the HDHP deductible is met. Common disqualifiers:

• A general-purpose Flexible Spending Account (FSA) -- yours, or your spouse's -- counts as disqualifying coverage. A spousal FSA disqualifies you because it can typically reimburse your own medical expenses.
• A spouse's non-HDHP health plan that covers you (for example, as a dependent on their family plan).
• Tricare or VA medical benefits received in the last three months for non-service-connected care.
• A Health Reimbursement Arrangement (HRA) that pays first-dollar for medical costs, unless it is structured as a "Limited Purpose" or "Post-Deductible" HRA.

Coverage that is permitted alongside HDHP and an HSA:

• Dental, vision, and long-term care insurance.
• Disability insurance, accident insurance, and specific-disease policies (such as cancer or critical-illness coverage).
• A Limited Purpose FSA (LPFSA) that pays only dental and vision.
• A Post-Deductible FSA that pays nothing until you have met the statutory HDHP minimum deductible.
• Coverage under workers' compensation.

Two practical implications:

1. During open enrollment, check whether your employer offers an HSA-compatible LPFSA. If you have a chronic dental or vision expense, an LPFSA still gives you a separate pre-tax bucket on top of your HSA.
2. If your spouse's employer offers a general-purpose FSA, your spouse should switch to an LPFSA (or skip the FSA) the year you want HSA contributions.

If someone else can claim you as a dependent on their federal tax return, you cannot contribute to your own HSA -- even if you otherwise pass the HDHP and other-coverage tests. This rule trips up a few specific groups:

• College students under 24 who are still claimed by their parents.
• Adult children under 26 on a parent's HDHP family plan who are also still claimed as a tax dependent.
• Adult dependents (a parent or relative) being claimed by a working family member.

Important nuance: an adult child can be on the parent's HDHP family plan for health insurance purposes but not a tax dependent. If the child is not claimed as a dependent (because they earn enough to file as independent, for example), they can open their own HSA and contribute up to the family limit -- $8,750 in 2026 -- because they are covered under a family HDHP. The IRS treats them as having family coverage even though the policy is in the parent's name.

This is a major planning opportunity for families with adult children on the family HDHP: each non-dependent adult child on the policy can open their own HSA and contribute the full family limit, on top of the parent's contribution to their own HSA.

Most people are not HSA-eligible for a perfect 12 months. Mid-year job changes, plan switches, marriage, and Medicare enrollment all change eligibility. The default rule -- without the last-month rule (Section 8) -- is straightforward:

Prorated annual limit = (Annual limit / 12) x months you were HSA-eligible on the first day of the month.

The same proration applies to the age-55 catch-up contribution: $1,000 / 12 = $83.33 per eligible month.

Math behind the last row (mixed coverage): self-only for 6 months ($4,400 / 12 x 6 = $2,200) plus family for 6 months ($8,750 / 12 x 6 = $4,375) totals $6,575. When tiers change mid-year, prorate each tier's limit by the months at that tier and sum them.

Use the HSA Calculator to run your exact scenario -- it handles tier changes, the age-55 catch-up, and the last-month rule.

Section 223(b)(8) of the Internal Revenue Code gives partial-year contributors a powerful option: if you are HSA-eligible on December 1, you may contribute the full annual limit for the year, regardless of how few months you were actually eligible.

The price is a 13-month testing period. You must remain HSA-eligible from December 1 of the contribution year through December 31 of the following year. Break eligibility during that window and the over-contributed portion becomes:

• Taxable income in the year you broke eligibility, and
• Subject to a 10% additional tax (not the 20% non-medical-withdrawal penalty -- a separate, lower penalty in this case).

When the last-month rule is worth it:

• You started an HDHP late in the year and you know you will keep it for at least 12+ more months.
• You are comfortable the 13-month testing period will hold (no planned Medicare enrollment, no expected job change to non-HDHP coverage).

When it is not worth it:

• You are within a year of Medicare-eligible age (65) and may enroll.
• You expect a job change to a non-HDHP plan within the next year.
• You may marry someone with a non-HDHP plan and switch coverage.

When in doubt, contribute only the prorated amount. The lost contribution room is small compared to the tax-plus-penalty cost of a broken testing period.

Run through each row. Any "Disqualifies" entry that applies to you means you cannot contribute to an HSA for the months in which that condition is true.

Maria, age 52, switches jobs on July 1, 2026. Her new employer's plan is HSA-qualified family HDHP with a $3,500 deductible and $14,000 out-of-pocket maximum. Her old employer's plan was a PPO with no HSA. Her spouse has dental and vision insurance only -- no FSA. Neither is on Medicare or claimed as a dependent.

Eligibility check for each month:

Maria has 6 eligible months (July through December). Her contribution options for 2026:

• Prorated (default) limit: $8,750 / 12 x 6 = $4,375.
• Last-month rule limit: $8,750 if she is HSA-eligible on December 1, 2026 (she is). The testing period runs December 1, 2026 through December 31, 2027 -- she must stay on an HSA-qualified HDHP family plan for all of 2027 and pass the other three tests every month.

If Maria is confident she will keep her new HDHP through 2027 and is not approaching Medicare age, the last-month rule unlocks an extra $4,375 in tax-deductible contribution room. If there is any chance she switches plans or her spouse's employer offers a general-purpose FSA next year, the prorated $4,375 is the safer call.

Run your own numbers with the HSA Calculator, then read the 2026 HSA Contribution Limits guide for the catch-up rules and the full triple tax advantage.

Run through the four tests for the current month. If you pass all four, calculate your prorated limit -- or apply the last-month rule if you are confident you will stay HSA-eligible through the 13-month testing period. Then maximize the contribution to capture the triple tax advantage for 2026.

Open the HSA Calculator ->

• IRS - Rev. Proc. 2025-19 (2026 HSA & HDHP inflation-adjusted amounts)(opens in new tab)
• IRS - Publication 969 (Health Savings Accounts and Other Tax-Favored Health Plans)(opens in new tab)
• 26 U.S.C. Section 223 - Health Savings Accounts(opens in new tab)
• IRS - Form 8889 (Health Savings Accounts)(opens in new tab)
• Medicare.gov - How do I get Parts A & B?(opens in new tab)

Important Disclaimer

Disclaimer: This content is for educational and informational purposes only and does not constitute financial, tax, or legal advice. HSA eligibility rules depend on your specific health coverage, Medicare status, dependency status, and any FSAs or HRAs in your or your spouse's plans; you should consult a qualified tax professional or benefits administrator before contributing in a partial-year or last-month-rule situation. Figures cited reflect IRS Rev. Proc. 2025-19 and IRC Section 223 as understood at publication, including the 2026 HDHP thresholds and HSA contribution limits. While we strive for accuracy, laws and regulations change frequently. Data current as of June 2026.

Content reviewed by the Digital Calculator Team. Learn more about our accuracy standards.