Short answer: The affordability percentage is the maximum share of an employee’s income that their required contribution for self-only coverage can take for the coverage to count as “affordable” under the ACA employer mandate. For 2026 it is 9.96%.
Under the ACA’s employer mandate, applicable large employers (ALEs) must offer full-time employees affordable, minimum-value coverage or face potential penalties. Coverage is “affordable” if the employee’s required contribution for self-only coverage does not exceed the affordability percentage of their income.
The IRS adjusts this percentage every year. For 2026 it is 9.96% (it was 9.02% for 2025 and 8.39% for 2024).
Because employers usually don’t know an employee’s total household income, they may use one of three IRS-approved safe harbors to measure affordability against something they do know:
- W-2 wages (Box 1)
- Rate of pay (hourly rate or monthly salary)
- Federal poverty line (FPL)
Each safe harbor applies the same affordability percentage; they differ only in the income figure used.