Employer Plan Affordability Test: When W-2 Employees Can Claim Marketplace PTC

Most discussions of the ACA Premium Tax Credit assume it is only for people without employer coverage. That is not quite right. The rule under IRC § 36B(c)(2)(C) is that an employee is ineligible for PTC only if offered "minimum essential coverage" that is "affordable" and provides "minimum value." All three conditions must be met. The affordability condition is the one most commonly in question — and it is tied to a specific annual percentage that has varied meaningfully from year to year.

The affordability test measures the employee's required contribution for the lowest-cost plan option that covers only the employee (self-only coverage) against the employee's household income. The IRS publishes the applicable percentage each year in a Revenue Procedure. Recent values: 2023: 9.12%, 2024: 8.39%, 2025: 9.02% per Rev. Proc. 2025-25. The 2024 dip to 8.39% — lower than any prior year — reflected inflation in premiums relative to income across the workforce. For 2026, the percentage will be set in a subsequent Rev. Proc. that typically publishes in late summer for the upcoming plan year.

To run the test: multiply the employee's household income by the applicable percentage. If the employee's required monthly contribution for self-only coverage at the cheapest plan option (not the richest plan, not the family plan — the cheapest self-only plan) exceeds 1/12 of that product, the employer plan is "unaffordable." The employee may then decline the employer plan and enroll in a marketplace qualified health plan, claiming PTC if income is within the eligible range. If the employee was already enrolled in the employer plan and then realizes it was unaffordable, the employee can use the affordability test retroactively on Form 8962 to demonstrate PTC eligibility for the months enrolled on the marketplace.

Two common errors: First, employees test the wrong plan. The test uses the cheapest self-only plan available — not the plan the employee actually chose. An employee who enrolled in the Gold plan cannot argue unaffordability based on the Gold plan's premium if a Bronze self-only option is affordable. Second, employees confuse "household income" with "wages." Household income for ACA purposes is MAGI — including all taxable income of all members of the tax household, not just the employee's wages. A self-employed spouse with $40,000 in Schedule C income increases household income and can make an otherwise unaffordable employer plan suddenly affordable.

For employers, the affordability test also matters for the employer shared responsibility (ESR) under IRC § 4980H. An employer that offers unaffordable coverage to a full-time employee who then obtains PTC on the marketplace may owe the ESR penalty. The IRS provides three safe harbors for employers to test affordability: the W-2 wages safe harbor, the rate of pay safe harbor, and the federal poverty line safe harbor. These employer-safe-harbor calculations do not always match the employee's actual household-income test — an employee who passes the household-income test may still fail the employer's safe harbor calculation. The two tests run on different tracks.

For households with MAGI near the 400% FPL cliff, the employer plan affordability determination is a threshold gate. Clear the gate by demonstrating unaffordability, and marketplace PTC is available. Fail to clear it (plan is affordable), and PTC is zero regardless of whether the employee actually enrolls in the employer plan. The engine at acacliff.com reflects this gate: with `employerCoverageOffer: true` and the employer plan passing the affordability test, PTC is blocked. With `employerCoverageOffer: false` or an unaffordable offer, PTC opens based on MAGI vs. FPL.

The affordability percentage is not static — it has ranged from 8.39% (2024) to 9.86% (2019) over the ACA's lifetime, reflecting Congressional indexing formulas and inflationary adjustments. A 1% shift in the threshold can flip affordability determinations for millions of workers. The 2024 drop to 8.39% was notable: an employee with $60,000 household income and $430/month self-only premium was "affordable" under the 2023 rule (9.12% × $60,000 = $5,472/year = $456/month ≥ $430) but "unaffordable" under the 2024 rule (8.39% × $60,000 = $5,034/year = $419.50/month < $430). One percentage point unlocked PTC eligibility for that worker.

The affordability test applies month-by-month. An employee who starts a new job mid-year and becomes eligible for employer coverage in August is blocked from PTC only for August through December — the months of eligibility. January through July they can claim PTC if income falls in range. Form 8962 Lines 12-23 (monthly calculation) captures this precisely.

Minimum value is a separate test that often receives less attention: the employer plan must cover at least 60% of total allowed costs on average (the actuarial value equivalent of a Bronze plan). Most large employer plans easily pass minimum value. Small employer plans on the SHOP exchange may not always pass minimum value; verify by asking HR for the Summary of Benefits and Coverage, which must disclose whether the plan meets minimum value.

For households near the 400% FPL cliff, the employer plan affordability test is a gatekeeping threshold before the PTC cliff even becomes relevant. A worker who clears the affordability gate (unaffordable employer offer) then faces the standard PTC-cliff math. A worker blocked by an affordable employer offer never reaches the cliff — they are excluded from PTC at any income level.