White Paper · Plan Design

Executive summary

A benefits buyer comparing tax-advantaged options is usually handed a list of acronyms and asked to pick one. The list flattens a real distinction. A health savings account, a flexible spending account, and a health reimbursement arrangement are reimbursement vehicles. They hold money and release it against a substantiated medical expense. A fixed indemnity benefit is insurance: it pays a defined amount when a covered medical event is documented, funded through a pre-tax cafeteria election rather than a personal account balance.¹

These are not competing answers to one question. A reimbursement account asks whether an employee has medical spending to substantiate and the cash flow to fund the account in the first place. A fixed indemnity benefit asks whether a covered event occurred and was documented. The first rewards employees with discretionary income and the discipline to manage a balance; the second pays on an event without requiring the employee to fund and carry an account.²

Account-based models concentrate their value among higher-income, lower-turnover employees. For a workforce that is hourly, high-turnover, or contingent, the same models tend to sit unused, and the use-or-lose feature of the flexible spending account can convert a benefit into a forfeiture. The fixed indemnity structure was built for the workforce the account models reach least well. This paper compares the mechanics, the funding, and the tax treatment of each, then maps each to the workforce it fits. It does not argue one structure is superior in the abstract; it argues the structure should follow the workforce, and it names the one tax question at the frontier that remains open rather than resolving it by assertion.

Two mechanics, two questions

What triggers a payment

The cleanest way to compare these models is to ask what triggers a payment under each, because the trigger is where the legal mechanics diverge.

In a reimbursement model, the trigger is a substantiated expense. The employee incurs a cost for medical care, submits documentation, and is reimbursed from an account that the employee or employer funded. The governing question is whether the expense qualifies as medical care under Section 213(d) and whether it was actually incurred. No qualifying expense, no reimbursement.³

In a fixed indemnity model, the trigger is a covered event. The carrier pays a fixed, predetermined amount when a defined medical event occurs and is documented, without regard to the size of any bill. The payment is insurance proceeds from an insurer that bears the risk of loss, not a return of the employee's own set-aside funds.⁴

The reimbursement family

HSA, FSA, HRA, and the POP election

The reimbursement vehicles share a logic but differ in funding, ownership, and constraint. The health savings account is employee-owned and portable, available only to an employee enrolled in a qualifying high-deductible plan, with a balance that carries forward indefinitely.⁵ The health flexible spending account is funded by salary reduction, makes the full election available from day one, and is subject to the use-or-lose rule.⁶

The health reimbursement arrangement is employer-funded and employer-owned; unused amounts generally do not vest in the employee.⁷ The premium-only election is the narrowest of the group: a Section 125 election that lets an employee pay a premium with pre-tax dollars. It holds no balance and pays no benefit.⁸ Across all four, money must go in before anything comes out, and what comes out is capped at what was substantiated.

The fixed indemnity mechanic

A chain of Code sections, settled for decades

The fixed indemnity benefit reaches the employee through a chain that has been settled for decades, and the chain is worth tracing because its defensibility rests on each link.

Section 105(b) is the documentary hinge: the favorable treatment depends on a real, substantiated medical event tied to documented medical care, which is why the program is administered against standard medical coding rather than paying cash on a self-reported event.⁹ The arrangement is fully insured, an A-rated carrier bearing the risk of loss, and is offered on a noncoordinated basis, which preserves its status as an excepted benefit.¹⁰

Where each one fits

The structure follows the workforce

The comparison resolves into a single practical question: which structure fits the workforce in front of you. The answer turns on cash flow, on participation, and on the cost of turnover, and different workforces call for different structures.

For a salaried, stable, higher-income workforce, the account models work as designed: these employees can fund a health savings account, absorb the high deductible it requires, and treat it as a long-term portable vehicle. For an hourly, high-turnover, or contingent workforce, the same models reach fewer people and serve them less well, for reasons that are structural rather than a matter of enrollment effort.¹²

The tax treatment, side by side

On one axis, without overclaiming

Because the tax treatment is where buyers are most often misled, it is worth setting the models side by side on that single axis, in plain terms.

The health savings account offers the most complete treatment of the reimbursement group: contributions pre-tax or deductible, growth untaxed, qualified distributions untaxed.¹³ The flexible spending account and the premium-only election deliver a pre-tax contribution that reduces income and payroll-taxable wages, the FSA bounded by use-or-lose and the POP limited to the premium it shelters. The health reimbursement arrangement delivers employer-funded reimbursements excluded under Sections 105 and 106. In each case the favorable treatment attaches to a return of set-aside funds against substantiated expense.¹⁴

More favorable in one respect, more bounded in another. The premium is sheltered like the others, but the benefit is insurance proceeds rather than a return of the employee's own balance, and the Section 213(d) boundary is stated plainly rather than papered over.¹⁵

The frontier

The one question that remains open

One question on this axis is genuinely open, and the standard of this series is to name it rather than resolve it by assertion. Whether the includable excess, beyond being gross income, is also wages subject to withholding and to Social Security and Medicare tax, is a question no court has decided for an arrangement that pays on a substantiated medical event.

The stronger reading of the statute is that it is not wages. Wages are remuneration for services performed, and an amount paid because a medical event occurred is not paid in return for services.¹⁶ For the contrary result to prevail, several specific things would each have to happen.

1. The question would first have to be litigated.

2. A court would have to adopt the wage treatment the Service has asserted only in a non-precedential Chief Counsel Advice, guidance the agency's own manual treats as binding on no one.¹⁷

3. The court would have to read the wage statutes against the ordinary meaning of remuneration for services.

4. And it would do so after Loper Bright withdrew the deference that once would have eased the agency's reading.¹⁸

The record is not one-sided

In 2023 the Service proposed an amendment to the Section 105(b) regulation that would have settled the question against the taxpayer. It did not finalize that amendment in the April 2024 final rule, but cautioned that the absence of a final rule should not be read as approval of current practices. Those facts keep the question open.¹⁹