HSA, HRA, and FSA: Payroll Processing Differences Explained
6/9/2026
These three accounts are frequently discussed as interchangeable tax-advantaged health accounts. From payroll's perspective they are almost nothing alike. They differ in who funds them, which wage bases they reduce, whether the money is portable, who bears the risk of loss, and — critically — whether the tax treatment depends on how the deduction is routed rather than on the account itself.
The Comparison
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HSA
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HRA
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Health FSA
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Funded by
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Employee, employer, or both
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Employer only
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Employee, employer optional
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Requires HDHP enrollment
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Yes
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No
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No
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2026 contribution limit
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$4,400 self-only / $8,750 family
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No statutory limit
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$3,400
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Age 55+ catch-up
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$1,000
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—
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—
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Employee-owned
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Yes
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No
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No
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Portable at termination
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Yes
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No
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Generally no
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Funds roll over
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Yes, indefinitely
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Per plan design
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Up to $680 carryover, or a grace period
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Full amount available upfront
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No — only amounts contributed
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Per plan design
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Yes — uniform coverage
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Risk of loss on termination
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None — employee keeps it
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Employer keeps unused
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Employer bears the loss
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Payroll deduction
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Yes
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No
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Yes
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Three rows drive most of the payroll consequences: an HRA involves no payroll deduction at all, an HSA is the employee's property, and a health FSA puts the risk of loss on the employer.
HSA: The Routing Trap
An HSA is an individual account owned by the employee, requiring enrollment in a qualifying high-deductible health plan. The employee keeps it regardless of employment.
For payroll, the decisive question is how the contribution is routed:
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Routing
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FIT wages
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Social Security
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Medicare
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FUTA / SUI
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Through a Section 125 cafeteria plan
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Reduces
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Reduces
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Reduces
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Reduces
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Direct payroll deduction outside a cafeteria plan
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Reduces
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No
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No
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No
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Same account, same dollars, materially different result. Routing through the cafeteria plan also saves the employer its 7.65% FICA matching share — which is why virtually every employer should route HSA contributions through the plan, and why discovering that they are not is a genuine finding worth acting on.
Employer contributions to an HSA are excluded from the employee's income when made under a cafeteria plan or under comparable-contribution rules.
Eligibility is the employee's responsibility but the employer's problem. Contributions are permitted only for HSA-eligible individuals — enrolled in a qualifying HDHP, not enrolled in Medicare, not claimed as a dependent, and without disqualifying other coverage. Two specific triggers payroll should watch:
- Medicare enrollment ends HSA eligibility, and it commonly coincides with an employee turning 65 while continuing to work
- A general-purpose health FSA — the employee's own or a spouse's — is disqualifying coverage. This is the most common accidental disqualification.
Excess contributions carry an excise tax on the employee unless corrected. Our HSA Training & Certification Program covers eligibility and administration.
HRA: No Payroll Deduction
An HRA is employer-funded only. Employees may not contribute, and there is no payroll deduction — which means payroll's involvement is limited but not zero.
Key characteristics:
- Reimbursements for qualified medical expenses are excluded from income when the arrangement satisfies the applicable requirements
- The employer sets the amount, the eligible expenses, and whether unused amounts carry forward
- Unused funds remain with the employer on termination
- Not portable
Several HRA designs exist with different rules — including ICHRA, which reimburses individual market premiums, EBHRA, a limited excepted-benefit design, and QSEHRA, available to smaller employers.
Payroll's actual involvement:
- Reimbursements should not be run as taxable wages. Where an HRA reimbursement is processed through payroll for convenience, it must be coded as a non-taxable reimbursement, not as compensation.
- A non-compliant arrangement becomes taxable. An arrangement that fails its design requirements — most often by reimbursing individual premiums outside a permitted structure — produces taxable wages for every participant.
- Coordination with HSA eligibility. A general-purpose HRA is disqualifying coverage for HSA purposes. Only limited-purpose designs preserve HSA eligibility.
Health FSA: Employer Bears the Risk
A health FSA is funded by employee salary reduction through a cafeteria plan, with optional employer contributions. It reduces all four wage bases.
The two rules that distinguish it operationally:
Uniform coverage. The full annual elected amount must be available from the start of the plan year regardless of contributions to date. An employee electing $3,400 who terminates in February having contributed $283 may already have been reimbursed the full $3,400.
The employer absorbs the loss. In that scenario the employer generally cannot recover the difference from the employee. This is the trade-off for the tax treatment, and it is why FSA elections carry real employer risk that HSA contributions do not.
Use-or-lose, relaxed two ways. A plan may offer a carryover of up to $680 for 2026, or a grace period of up to 2½ months — not both.
A general-purpose health FSA disqualifies HSA eligibility. A limited-purpose FSA — restricted to dental and vision, for instance — preserves it. Employees enrolling in both without understanding this is a routine problem, and it is worth flagging at open enrollment rather than discovering at year end.
See our cafeteria plans guide for the Section 125 framework.
Dependent Care FSA Is Different Again
Frequently grouped with the health FSA and governed by different rules:
- 2026 limit $7,500, or $3,750 for married filing separately — a substantial increase from the long-standing $5,000
- No carryover
- No uniform coverage — reimbursement is limited to amounts actually contributed, so the employer bears no risk of loss
- Its own mid-year change rules, which are broader than the health FSA's and include changes in the cost or coverage of dependent care
- Its own nondiscrimination testing
The absence of uniform coverage is the practical distinction: a dependent care FSA cannot create the termination loss that a health FSA can.
HSA Mid-Year Eligibility and Proration
HSA contribution limits are annual, but eligibility is determined monthly — on the first day of each month — which creates proration questions payroll is asked to resolve.
The general rule is that the annual limit is prorated by the number of months the individual was HSA-eligible. Someone who becomes eligible in July has roughly half the annual limit available.
There is an important alternative, the last-month rule: an individual who is HSA-eligible on the first day of the last month of the tax year may generally be treated as eligible for the entire year, permitting a full annual contribution regardless of when eligibility began. The condition is a testing period — the individual must remain eligible for the following twelve months. Failing the testing period causes the excess to become taxable income plus an additional tax.
Why this matters for payroll: an employee who enrolls in an HDHP in October and wants to contribute the full annual amount through year-end payroll deductions may be relying on the last-month rule without knowing its condition. Payroll cannot police that decision, but it should not encourage it either. The safe posture is to administer the deduction the employee elects, within the plan's limits, and direct the eligibility question to the employee and their tax advisor.
Mid-year coverage tier changes also affect the limit — moving from self-only to family coverage changes the annual maximum, and the proration follows the monthly eligibility pattern.
Turning 65 is the eligibility event payroll should actively monitor. Medicare enrollment ends HSA eligibility, and it frequently coincides with an employee continuing to work past 65. Contributions after Medicare enrollment are excess contributions carrying an excise tax on the employee. A birthday-based flag is a cheap and effective control.
Our HSA Training & Certification Program covers eligibility and proration in detail.
Termination Handling
Each account behaves differently at separation, and this is where payroll errors concentrate:
HSA. The employee keeps the account. Stop payroll contributions as of the correct date. Nothing to recover, nothing to reconcile.
HRA. Unused amounts remain with the employer, subject to any continuation the plan provides.
Health FSA. Contributions stop. The employee may have been reimbursed more than contributed, and the employer generally absorbs it. COBRA continuation may be available for the FSA in some circumstances, which is a plan-design question.
Dependent care FSA. Contributions stop; reimbursements are limited to contributions made.
A common error is continuing a deduction past the termination date for any of these, or stopping an HSA contribution mid-period without prorating correctly.
The Payroll Configuration Checklist
- [ ] Confirm HSA contributions are routed through the cafeteria plan — verify this rather than assuming it
- [ ] Confirm HSA deduction codes reduce all four wage bases if routed through the plan, and income tax only if not
- [ ] Confirm health FSA and dependent care FSA codes reduce all four wage bases
- [ ] Confirm HRA reimbursements are not coded as taxable wages
- [ ] Load 2026 limits: HSA $4,400 / $8,750 plus $1,000 catch-up; health FSA $3,400 with $680 carryover; dependent care $7,500
- [ ] Enforce the HSA age 55 catch-up eligibility correctly
- [ ] Flag employees enrolled in both an HSA and a general-purpose health FSA
- [ ] Flag employees reaching 65 or enrolling in Medicare while contributing to an HSA
- [ ] Confirm the plan offers a carryover or a grace period, not both
- [ ] Confirm dependent care reimbursements are limited to amounts contributed
- [ ] Stop contributions accurately on termination and coverage changes
- [ ] Reconcile contributions per payroll to the administrator and custodian records quarterly
Which Account Fits Which Situation
Employees ask payroll to compare these accounts, and while the choice is theirs, understanding the trade-offs makes the conversation useful rather than deflecting.
The HSA is the strongest account where the employee qualifies. It is the only one that is employee-owned, fully portable, and rolls over indefinitely — and routed through a cafeteria plan it reduces all four wage bases. The constraint is real, though: it requires HDHP enrollment, which means a higher deductible and more out-of-pocket exposure before coverage engages. For an employee with predictable high medical costs and limited cash reserves, the HDHP requirement can outweigh the tax advantage.
The health FSA suits predictable expenses within one year. Its distinguishing advantage is uniform coverage — the full election is available immediately, which the HSA cannot match early in a year. Its distinguishing risk is forfeiture beyond the carryover. It fits an employee who can forecast the year's expenses reasonably well.
The HRA is not a choice the employee makes. It is an employer design decision, funded entirely by the employer, and the employee's only real question is what it covers.
A limited-purpose FSA alongside an HSA is the combination employees most often miss. It preserves HSA eligibility while providing immediate access to funds for dental and vision, which addresses the HSA's early-year liquidity gap without disqualifying it.
Where payroll should stop: eligibility determinations, tax projections, and recommendations. The appropriate posture is to explain the mechanical differences accurately — funding source, portability, rollover, and when funds are available — and direct the personal decision to the employee, the plan administrator, or their tax advisor.
Frequently Asked Questions
What is the difference between an HSA, HRA, and FSA?
An HSA is an employee-owned account requiring high-deductible health plan enrollment, funded by employee or employer, fully portable, with funds rolling over indefinitely. An HRA is employer-funded only with no payroll deduction, is not portable, and unused amounts remain with the employer. A health FSA is funded by employee salary reduction through a cafeteria plan, is generally not portable, and must make the full annual election available from the start of the plan year.
Do HSA contributions reduce FICA taxes?
Only if routed through a Section 125 cafeteria plan. Contributions made through the plan reduce federal income tax, Social Security, Medicare, and unemployment wages, and also save the employer its 7.65% matching share. A direct payroll deduction to an HSA outside a cafeteria plan reduces income tax only. Same account and same dollars, but a materially different result determined entirely by the routing.
Can an employee have both an HSA and a health FSA?
Not with a general-purpose health FSA — that is disqualifying coverage for HSA eligibility, and it applies to a spouse's general-purpose FSA as well. A limited-purpose FSA restricted to expenses such as dental and vision preserves HSA eligibility. This is the most common accidental HSA disqualification and is worth flagging at open enrollment rather than discovering at year end.
What is the uniform coverage rule?
A health FSA must make the full annual elected amount available from the beginning of the plan year regardless of contributions made to date, so an employee who terminates early may have been reimbursed far more than they contributed. The employer generally absorbs that shortfall and cannot recover it. Dependent care FSAs have no uniform coverage requirement — reimbursement is limited to amounts actually contributed — so they carry no equivalent employer risk.
What are the 2026 HSA and FSA limits?
HSA contributions are limited to $4,400 for self-only coverage and $8,750 for family coverage, with an additional $1,000 catch-up for those age 55 and older. The health FSA limit is $3,400 with a permitted carryover of up to $680. The dependent care FSA limit is $7,500, or $3,750 for married filing separately, a significant increase from the prior $5,000.
How is an HRA handled in payroll?
There is no payroll deduction, because an HRA is employer-funded only. Payroll's involvement is limited to ensuring that any reimbursement processed through payroll is coded as a non-taxable reimbursement rather than as compensation, and to understanding that a general-purpose HRA is disqualifying coverage for HSA eligibility. An arrangement that fails its design requirements produces taxable wages for every participant.
Going Deeper
Contribution limits are adjusted annually and HRA design rules are detailed and evolving. Verify current-year figures and confirm each arrangement's design with the plan administrator before configuring payroll deduction codes.
