HSA Contribution Optimizer
Example: IRS annual HSA limit (self or family): 4300 $ · Employer HSA contribution: 750 $ · Expected medical spending this year: 3000 $ · Your marginal tax rate: 24 %
| Recommended contribution | $3,550 |
| Income tax you save | $852 |
| Total going into your HSA | $4,300 |
Worked example
Say the IRS self-only limit is $4,300 this year and your employer drops in $750. To hit the ceiling you should contribute the remaining $3,550 from your own paychecks. In a 24% marginal bracket, that $3,550 of pre-tax money cuts your income tax by about $852, so maxing the account really costs you closer to $2,698 in take-home pay. Altogether $4,300 lands in the HSA — the full annual maximum — even though your own out-of-pocket share was only $3,550.
Frequently asked questions
Does my employer contribution count toward the limit?
Yes. The IRS limit is the combined total from all sources, so any money your employer or a wellness program adds reduces how much room you have left. That is exactly why this tool subtracts the employer amount first — contributing the full limit yourself on top of employer money would create an excess contribution and a penalty.
How is this different from an HSA growth projection?
A growth projection answers what your balance could become in 20 years if you invest it. This tool answers a narrower, more immediate question: how many dollars to elect this specific year to reach the maximum after employer money, and the tax that election saves right now. It is a payroll-form number, not a retirement forecast.
Should I contribute the maximum even if my medical spending is low?
Often yes, if you can afford it. Unused HSA money rolls over forever and can be invested, so a low-spending year is a chance to build a tax-free medical nest egg rather than a reason to under-fund. The one time to hold back is if you truly need the cash flow this year, since the tax break is not worth going into debt for.
What are the self-only versus family limits?
The IRS publishes two figures each year — a lower limit for self-only high-deductible coverage and a higher one for family coverage — and both rise with inflation. People 55 and older can add a catch-up contribution on top. Enter whichever limit matches your coverage in the limit field, and add the catch-up to it if you qualify.
When do I have to make the contribution?
You can generally fund your HSA for a given tax year up until that year's tax-filing deadline in April, not just by December 31. That gives you flexibility to top up to the limit after the year ends once you know your final numbers. Payroll contributions, though, must go in during the calendar year through your employer's plan.