IRS Rules Governing HDHPs and HSAs

The Internal Revenue Service sets the statutory framework that determines whether a health plan qualifies as a High-Deductible Health Plan and whether an account holder can make tax-advantaged contributions to a Health Savings Account. These rules, rooted in Section 223 of the Internal Revenue Code, govern minimum deductibles, out-of-pocket ceilings, contribution limits, and the conditions under which coverage disqualifies a person from HSA eligibility. Understanding the IRS framework is essential for employers designing benefit packages, employees making enrollment decisions, and anyone managing an HSA across multiple tax years.

Definition and scope

Under 26 U.S.C. § 223, a High-Deductible Health Plan is defined by two numerical thresholds that the IRS adjusts annually for inflation: a minimum annual deductible and a maximum annual out-of-pocket limit. For 2024, the IRS set the minimum deductible at $1,600 for self-only coverage and $3,200 for family coverage, while the out-of-pocket maximum cannot exceed $8,050 for self-only or $16,100 for family coverage (IRS Revenue Procedure 2023-23).

A plan that fails either threshold — meaning its deductible falls below the floor or its out-of-pocket cap exceeds the ceiling — does not qualify as an HDHP under IRS rules, and the account holder therefore cannot make or receive pre-tax HSA contributions for any month the disqualifying coverage is in force. The IRS definition of an HDHP is precise enough that even a single month of non-qualifying coverage can affect annual contribution calculations.

The scope of these rules extends to all plan types — fully insured, self-funded HDHP arrangements, and individual market plans — as long as the plan is designed to provide coverage for medical expenses as defined under IRC § 213(d).

How it works

The IRS framework operates through two interlocking mechanisms: plan qualification and individual eligibility.

Plan qualification is determined at the plan design level. The plan sponsor or insurer must ensure the deductible structure meets the statutory minimums before any dollar of covered medical expenses is paid on the enrollee's behalf, with one critical exception: HDHP preventive care covered before the deductible is explicitly permitted by statute and IRS guidance. Under IRS Notice 2004-23 and subsequent guidance, plans may cover preventive services at first dollar without violating HDHP status.

Individual eligibility is determined monthly. A person is HSA-eligible in a given month if, on the first day of that month, all of the following conditions are met:

The individual is enrolled in a qualifying HDHP.
The individual has no disqualifying coverage — meaning no general-purpose health FSA, Medicare enrollment, or non-HDHP plan covering the same expenses.
The individual is not claimed as a dependent on another person's tax return.
The individual is not enrolled in any Veterans Affairs health benefits received within the preceding 3 months, unless limited to service-connected conditions.

HSA contribution limits are also set by the IRS annually. For 2024, the IRS established a contribution ceiling of $4,150 for self-only HDHP coverage and $8,300 for family coverage, plus a $1,000 catch-up contribution for individuals age 55 or older (IRS Revenue Procedure 2023-23). Contributions exceeding these limits are subject to a 6% excise tax under IRC § 4973.

The HSA triple tax advantage explained is only available when both plan qualification and individual eligibility are satisfied simultaneously.

Common scenarios

Scenario 1: Mid-year enrollment in Medicare
An individual who turns 65 and enrolls in Medicare Part A retroactively — which Medicare can make retroactive up to 6 months — loses HDHP eligibility for those same months. Contributions made during a retroactively disqualified period trigger the 6% excise tax and must be withdrawn with allocated earnings to avoid compounding the penalty.

Scenario 2: Spouse enrolled in a general-purpose FSA
If a spouse is enrolled in a general-purpose Health Flexible Spending Account through their own employer, the IRS treats the FSA as disqualifying coverage for the other spouse, even if the HDHP-enrolled spouse is not formally enrolled in the FSA. The FSA can legally reimburse the HDHP spouse's eligible expenses, which is the operative disqualification. Converting the spouse's FSA to a limited-purpose FSA (covering only dental and vision) resolves the conflict.

Scenario 3: Employer HSA contributions and the last-month rule
Under the "last-month rule" in IRC § 223(b)(8), an individual who is HSA-eligible on December 1 of a tax year can contribute the full annual limit regardless of how many months of qualifying coverage were in force earlier that year. However, the individual must then remain HDHP-eligible through December 31 of the following year — the "testing period" — or the excess contributions and a 10% penalty tax become due.

Scenario 4: Family plan with embedded deductibles
Some family HDHPs use an embedded deductible structure in which individual family members have a deductible lower than the family deductible. IRS rules require that the embedded individual deductible cannot be lower than the statutory minimum for family coverage ($3,200 in 2024). A plan with a $1,000 embedded individual deductible within a family plan fails HDHP qualification because that embedded amount falls below the family floor.

Decision boundaries

The IRS rules create clear boundaries that separate qualifying from disqualifying situations. The distinctions most likely to affect enrollment decisions include:

HDHP vs. non-HDHP coverage in the same household: A person enrolled in a qualifying HDHP but also covered under a spouse's non-HDHP plan — even as a dependent — loses HSA eligibility. This is different from HDHP vs. PPO key differences at the plan level; the issue here is concurrent coverage, not plan design.

Telehealth and temporary safe harbor provisions: Congress periodically enacted temporary provisions allowing HDHPs to cover telehealth services before the deductible without disqualifying HSA eligibility. These provisions are not permanent features of the IRC and must be tracked against active legislation. The HDHP telehealth coverage and first dollar benefits page addresses current legislative status in detail.

HSA vs. FSA boundary: A general-purpose FSA — even a $0-balance account that was simply opened during open enrollment — is treated as disqualifying coverage from the first day the plan year begins. The HSA vs. FSA key differences analysis describes how the two account types interact under IRS rules.

Annual threshold updates are the single most administratively consequential aspect of compliance. Employers and plan administrators must verify plan documents against each year's published figures; a plan not amended to reflect a new minimum deductible automatically falls out of HDHP status. The annual IRS HDHP and HSA threshold updates page tracks each revision as the IRS publishes revenue procedures.

Navigating these rules requires a working understanding of how HDHP structure and HSA eligibility interact — a relationship covered comprehensively across the HDHP Authority resource index.

References

The law belongs to the people. Georgia v. Public.Resource.Org, 590 U.S. (2020)