Can Employees Still Contribute to Last Year’s HSA?

As tax season approaches, many employers focus on payroll reporting, compliance and year‑end clean‑up. But there’s another timely opportunity that often goes overlooked: employees may still be able to make Health Savings Account (HSA) contributions for the prior tax year up until the federal tax‑filing deadline. 

For employers, this moment presents a valuable chance to reinforce financial wellness, help employees avoid costly mistakes and strengthen trust in your benefits program, particularly for employees approaching retirement, where HSA rules become more complex. 

Here’s what employers need to know, and how you can help employees decide whether a last‑minute HSA contribution makes sense. 

The basics: Prior‑year HSA contributions 

Employees who were HSA‑eligible during the prior tax year may be able to make or increase contributions for that year up until the tax‑filing deadline (generally mid‑April). 

This includes: 

• Employees who did not max out their HSA through payroll deductions 

• Employees who experienced mid‑year coverage changes 

• Employees who became more aware of HSA advantages late in the year 

Importantly, these contributions are reported for the prior tax year, even though the money is deposited in the current calendar year. 

Where employers can add value: Helping employees decide 

Not every employee should automatically make a last‑minute contribution. Employers can help employees understand when it makes sense and when it may not. 

1.  Confirm HSA eligibility for the prior year. Employees must have been enrolled in an HSA‑qualified high‑deductible health plan (HDHP) and not covered by disqualifying coverage during the months for which they are contributing. 
    
   Employer reminder tip: Encourage employees to confirm eligibility before contributing, especially if they changed plans, added coverage through a spouse or experienced a life event. 

2. Highlight the 55+ catch‑up opportunity: Employees age 55 or older (and not enrolled in Medicare) are eligible to contribute an additional catch‑up amount up to $1,000 beyond the standard IRS limit.

   This can be especially meaningful for: 

   • Late‑career employees accelerating retirement savings 

   • Employees planning for higher healthcare costs in retirement 

   • Employees who under‑contributed earlier in the year 

   Employer reminder tip: Frame HSAs not just as a spending account, but as a long‑term healthcare savings tool that can complement retirement planning.

3. Address Medicare timing, clearly and carefully. Employees cannot contribute to an HSA once they are enrolled in Medicare, including Medicare Part A. In addition, Medicare Part A coverage can be retroactive up to six months, which may create inadvertent excess contributions if employees are not aware of the timing rules. 

   Employer reminder tip: Encourage employees who are approaching age 65 or planning to enroll in Medicare to pause and seek guidance before making additional HSA contributions. This is particularly important for organizations with a large pre‑Medicare population or phased‑retirement workforce. 

4. Reinforce the long‑term value of HSAs. Even if employees don’t need immediate reimbursement, HSAs can be a powerful tool for future healthcare expenses, including in retirement. 

Key points employers can reinforce: 

• HSA funds do not expire 

• Funds can be used for qualified medical expenses in retirement 

• After age 65, HSA funds can be used for non‑medical expenses without penalty (though income tax applies) 

• HSAs can help cover costs that traditional retirement accounts cannot, such as premiums, prescriptions and out‑of‑pocket expenses 

Employer reminder tip: Position HSAs as part of a broader health and wealth strategy, not just an annual benefits decision. 

Employer takeaways 

Tax season is more than a compliance checkpoint; it’s a strategic moment for employers to help employees make informed decisions that support both financial wellness today and healthcare security tomorrow. 

By proactively educating employees about prior‑year HSA contributions and the considerations that come with them, improve engagement and reinforce the long‑term value of their benefits strategy. 

Learn how personalized guidance and decision support can help employees navigate HSAs, Medicare and retiree healthcare with confidence with Via Benefits. 

*WTW is not an accounting firm or a law firm and does not provide any legal, accounting or tax advice or opinions. All accounting information should be verified by your accountants, and you should consult your legal counsel and/or tax advisors with respect to any legal or tax questions.