HSA eligibility is stricter than most people realize. Four conditions must all be true, and the disqualifiers catch people who assume an HDHP is enough.
Most people assume that if they have a high-deductible health plan, they can fund an HSA. That is one of four conditions, and the other three disqualify more people than anyone expects — including plenty who have been contributing for years without realizing they should not have been.
Here is the complete test.
To be eligible to contribute to an HSA, all four of these must be true:
Miss any one and you cannot contribute for that month. Note the framing: this is about contributing. Everything already in the account stays yours, stays invested, and stays available for qualified expenses regardless.
"High deductible" is an IRS definition, not a marketing label. The plan has to meet minimum deductible and maximum out-of-pocket thresholds that the IRS sets each year — the current figures are in our guide to 2026 contribution limits.
Two things worth checking rather than assuming. First, a plan with a high deductible is not automatically HSA-qualified; it has to be designed as one. Second, your plan documents or HR should say so explicitly — look for "HSA-qualified" or "HSA-eligible," not just a big deductible number.
One large exception, new in 2026. From 1 January 2026, all individual-market ACA bronze and catastrophic plans count as HDHPs — even where the plan does not meet the minimum annual deductible requirement. That change made roughly 7.3 million marketplace enrollees eligible overnight, and it reverses the "a high deductible is not enough" rule for those plans specifically. It does not affect employer plans. Full detail in the 2026 HSA rule changes.
This is where most people get caught, and the most common trap is not their own coverage.
A general-purpose health FSA disqualifies you. This includes your spouse's general-purpose FSA, even if you are not enrolled in their health plan — because an FSA can reimburse expenses for the whole family, you are considered covered by it. This single rule disqualifies a large number of dual-income households who never realized it. A limited-purpose FSA (dental and vision only) does not disqualify you, and neither does a post-deductible FSA.
A spouse's non-HDHP family plan disqualifies you if it covers you. If your spouse's PPO includes you as a dependent, you are not HSA-eligible even if you also have your own HDHP.
Health Reimbursement Arrangements generally disqualify you, unless they are limited-purpose or post-deductible.
Veterans Affairs care disqualifies you if you received VA medical benefits in the previous three months — with an important exception: care for a service-connected disability does not disqualify you.
TRICARE disqualifies you outright. There is currently no TRICARE plan that qualifies as an HDHP for HSA purposes.
What is permitted alongside an HDHP: dental, vision, disability, long-term care, accident, and specific-disease coverage. Preventive care covered before the deductible is also fine — that is built into how HDHPs are designed.
Enrolling in any part of Medicare — including premium-free Part A — ends your ability to contribute. Not reduced; zero.
The trigger is enrollment, not age. If you are still working at 66, on your employer's HDHP, and have not enrolled in Medicare, you can keep contributing.
There is a retroactive-enrollment trap attached to this that catches people six months before they expect it. We cover it in detail in what changes at 65.
If someone else can claim you as a dependent on their tax return, you cannot contribute to an HSA — even if you have your own HDHP through your own job.
This matters most for adults in their early twenties. A 24-year-old on a parent's HDHP can be covered by it, but if the parents claim them as a dependent, they cannot fund their own HSA. If they are not claimed as a dependent, they can — and this is one of the more useful and least-known planning opportunities available, because the family-coverage limit applies rather than the self-only limit.
The test is applied on the first day of each month. You are eligible for that month if all four conditions hold on the 1st.
Your annual contribution limit is then prorated by how many eligible months you had. Become eligible on July 1 and you get roughly half the annual limit — unless you use the last-month rule, which has a testing period attached to it that we explain in the 2026 limits guide.
This is the reassuring part, and it is worth stating plainly because people panic about it.
Losing eligibility affects contributions only. It does not affect:
An HSA is not like an FSA. Nothing is forfeited, nothing expires, and there is no deadline. If you switch to a PPO next year, you simply stop contributing and keep everything else.
That last point is why the shoebox strategy still works for people who are no longer eligible to contribute. Every receipt from every year the account has been open remains reimbursable — which only helps if you actually still have the receipts.
It happens, most often because of a spouse's FSA that nobody connected to the HSA. The fix is a corrective distribution before your tax filing deadline; leave it and you face a 6% excise tax for every year it remains. See how to fix excess HSA contributions.
Ask yourself, for each month:
If the first answer is yes and the rest are no, you are eligible.
This article is general information, not tax advice. HSA eligibility depends on your specific plan documents and household situation. Confirm with your benefits administrator or a tax professional before contributing.