Short answer: Yes. If an employer allows HSA contributions through payroll on a pre-tax basis, they must allow employees to change their HSA contribution elections during the year, generally at least on a monthly basis.
Although Health Savings Account contributions are often made through an employer’s Section 125 cafeteria plan, they are treated differently from other cafeteria plan elections.
Health insurance premiums and health FSA elections are subject to the irrevocable election rule, meaning employees generally cannot change those elections mid-year unless they experience a qualifying life event.
HSA contribution elections are an exception. IRS guidance requires that employees be allowed to change their HSA salary reduction elections prospectively during the year. Employers typically satisfy this requirement by allowing changes at least once per month.
This rule applies even though HSA contributions are made on a pre-tax basis through payroll. An employer may impose reasonable administrative procedures, but it cannot lock employees into a fixed HSA contribution amount for the entire plan year.
Employees remain responsible for ensuring that total annual HSA contributions, including employer contributions, do not exceed the applicable IRS limit based on coverage type and eligibility.
Sources
- IRS, Notice 2004-50, Q&A-81 (HSA elections under cafeteria plans): https://www.irs.gov/pub/irs-drop/n-04-50.pdf
- IRS, Publication 969 – Health Savings Accounts: https://www.irs.gov/forms-pubs/about-publication-969
Content history
Originally published: January 29, 2026
Last reviewed: January 29, 2026