Common Employer Benefits

Mrs. Garcia came in with her W-2 and a question she’d been holding for two months.

“My HR lady said I have an FSA and an HSA,” she said. “I don’t really know the difference. Do I have to do anything with those on my taxes?”

The preparer looked at the W-2. Box 12 showed two entries: Code W — $1,200 and Code DD — $9,800.

“The W code is your HSA — that’s your Health Savings Account. Your employer put $1,200 into it this year. That flows through a separate form on your return. The DD is just your health insurance cost — informational, doesn’t affect your taxes.”

“What about the FSA?”

“An FSA doesn’t show up in Box 12,” the preparer said. “It already reduced your Box 1. It happened before your W-2 was calculated. Did you use all the FSA funds this year?”

Mrs. Garcia paused. “I think I left some in there.”

“Let’s talk about that.”

Employer benefits are one of the most underexplained areas of personal finance — and they directly affect the tax return. Clients use benefits all year without understanding how those benefits appear on the W-2, which ones reduce their taxable income, and which ones create obligations on the return. Your job is to know what to look for.

A traditional 401(k) allows employees to contribute a portion of their wages before income tax is calculated. The contribution reduces Box 1 (federal taxable wages) immediately. The client doesn’t pay income tax on those dollars now — they pay when they withdraw in retirement.

On the W-2: Code D in Box 12. The amount is the employee’s contribution for the year. Also look for the Retirement Plan checkbox in Box 13 — it should be checked if the employee participated in any employer retirement plan.

What the preparer checks: Did the contribution exceed the annual limit? For 2025, the limit is $23,500. Employees 50 or older can contribute an additional $7,500 in catch-up contributions ($31,000 total). Excess contributions are included in Box 1 but should not be. If the Code D amount exceeds the limit, flag it for the client to correct with their employer.

Box 13 retirement plan check matters for IRAs: If Box 13 is checked (retirement plan participant), the deductibility of a traditional IRA contribution phases out at certain income levels. For a single filer covered by a workplace plan in 2025, the IRA deduction begins phasing out at $79,000 of modified AGI. For MFJ where the contributing spouse is covered, phase-out starts at $126,000. Always check Box 13 before discussing IRA deductibility with any client.

A Roth 401(k) accepts after-tax contributions — meaning the money goes in after income tax is calculated. Box 1 is not reduced by Roth 401(k) contributions. The client pays tax now and withdraws tax-free in retirement (qualified distributions).

On the W-2: Code AA in Box 12. The amount is informational. It does not reduce Box 1 and does not create any current-year deduction. Box 13 Retirement Plan will also be checked.

Some clients contribute to both a traditional and a Roth 401(k) in the same year. You may see Code D and Code AA on the same W-2. The combined total of both cannot exceed the annual limit ($23,500 in 2025).

An HSA is a tax-advantaged savings account paired with a High Deductible Health Plan (HDHP). Contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. It’s one of the most tax-efficient accounts in the code.

How contributions reach the HSA: Three ways. (1) Through employer payroll, in which case they never appear in Box 1 at all and show up as Code W in Box 12. (2) Through the employee’s own direct contributions to the HSA account, which are deductible on the 1040. (3) Both — employer contributes some, employee contributes more directly.

Form 8889 is required for any return with an HSA. It reports total contributions (employer + employee), HSA distributions, and any taxable distributions. If you see Code W in Box 12, you must complete Form 8889.

2025 HSA contribution limits: $4,300 for self-only HDHP coverage. $8,550 for family HDHP coverage. Individuals 55 or older can contribute an additional $1,000. Total contributions from all sources (employer + employee) cannot exceed the limit. If the Code W amount is already at or near the limit, the client cannot make additional deductible contributions.

An FSA allows employees to set aside pre-tax dollars for qualified medical or dependent care expenses. Unlike an HSA, FSA funds must generally be used by year-end or they are forfeited (the “use it or lose it” rule), though some plans allow a grace period or limited rollover.

On the W-2: Healthcare FSA contributions reduce Box 1 and do not appear separately in Box 12. They are invisible on the W-2 — they’ve already been removed from wages. Dependent Care FSA (for childcare expenses) appears in Box 10 of the W-2. The Box 10 amount flows to Form 2441 (Child and Dependent Care Credit).

What the preparer checks: If Box 10 has an amount, the client used a Dependent Care FSA. This interacts with the Child and Dependent Care Credit. The FSA reduces the expenses eligible for the credit dollar-for-dollar. A client who had $5,000 in dependent care FSA funds and $7,000 in actual childcare expenses has $2,000 in eligible expenses remaining for the credit. Enter Box 10 accurately — software handles the credit interaction automatically once it’s populated.

Most employees who receive health insurance through their employer pay their share of premiums through pre-tax payroll deductions. This reduces Box 1 without any separate notation. Code DD in Box 12 shows the total cost of employer-sponsored health coverage (employer share + employee share) but is purely informational — it changes nothing on the return.

What matters for the return: If a client is self-employed and pays for their own health insurance, that’s a deduction we discuss in Module 5. For W-2 employees with employer coverage, the premiums are already excluded from Box 1 and there is nothing additional to claim. The exception: a client who also paid out-of-pocket premiums for supplemental insurance not offered through an employer — those may be deductible if the client itemizes.

Employers commonly provide a basic life insurance benefit — often one or two times the employee’s annual salary. The first $50,000 of employer-provided group term life insurance is excluded from wages. Any amount above $50,000 creates taxable income for the employee.

On the W-2: Code C in Box 12 reports the taxable value of coverage above $50,000. This amount is already included in Box 1, Box 3, and Box 5. It does not need to be entered separately. But seeing Code C tells you to verify: is the Box 1 amount higher than what the employee believes they earned? Yes — because the life insurance benefit is in there too.