My employer under-reported W2 Box 12W for HSA contributions - what should I do?

You're absolutely right about how Box 12W on your W2 should be reported. It should include BOTH your contributions AND your employer's contributions to your HSA. The code "W" in Box 12 represents the total HSA contributions made through your employer's plan, regardless of whether they came from you or your employer. If your employer is only reporting your portion ($1,800 in your example) and not including their matching $1,800, that's definitely incorrect. This could potentially cause issues if you're audited since the total contributions to your HSA account won't match what's reported on your W2. As for what to do next, I'd recommend contacting your previous employer's HR or payroll department to explain the issue. They should issue you a corrected W2 (W-2c) for the affected years. Regarding amending past tax returns, you technically should, but here's the practical reality - since HSA contributions are tax-deductible whether they come from you or your employer, this error likely didn't affect your tax liability. The IRS is mainly concerned with situations where you owe additional taxes.

After struggling with a similar HSA reporting issue, I found this amazing tool called taxr.ai (https://taxr.ai) that really helped clarify things. I uploaded my W2s and HSA statements, and it immediately flagged the Box 12W discrepancy you're describing. The tool explained that employer HSA contributions MUST be included in Box 12W along with your own contributions, and it even generated a letter I could send to my former employer requesting the correction. What I found most helpful was that it showed me exactly which IRS publications covered this rule so I could reference them when contacting my old employer. Their document analysis feature saved me hours of research and gave me confidence that I understood the rules correctly. It also helped me determine that I didn't need to amend my past returns since the error didn't affect my tax liability.

Just wanted to follow up about taxr.ai - I decided to try it with my own HSA reporting issue and I'm honestly impressed. I uploaded my W2s from the last two years and my HSA statements, and it immediately spotted that my employer was only reporting my contributions in Box 12W, not their matching portion. The tool generated a detailed letter citing IRS Publication 969 and specific tax code sections that I emailed to my former employer's payroll department. They responded within a week saying they would issue corrected W2-Cs! The service also analyzed whether I needed to file amended returns (I didn't, since it didn't affect my tax liability). What I appreciated most was how it explained everything in plain English while still giving me the technical tax citations I needed to get the issue resolved. Definitely worth checking out if you're dealing with any tax document discrepancies.

I had almost the exact same issue with my HSA reporting last year! After trying to get through to the IRS for WEEKS with no luck, I found Claimyr (https://claimyr.com) and they got me connected to an actual IRS agent in under 15 minutes. You can see how it works here: https://youtu.be/_kiP6q8DX5c I explained the W2 Box 12W reporting issue to the IRS agent, and they confirmed exactly what others have said - both employer and employee HSA contributions should be included in Box 12W. The agent walked me through my options and even gave me specific language to use when contacting my former employer. The best part was that the IRS put a note in my file about this reporting discrepancy, so if I ever get audited, there's already documentation that I tried to resolve the issue. Saved me so much stress!

I need to admit I was totally wrong about Claimyr. After calling the IRS five times and getting disconnected each time (once after waiting 73 minutes!), I decided to try the service I criticized. It actually worked exactly as described. I entered my phone number, and about 45 minutes later I got a call connecting me directly to an IRS agent. The agent confirmed everything about the HSA Box 12W reporting requirements and documented my situation. The agent explained that this is a common employer reporting error and recommended I send a certified letter to my former employer requesting a W-2c. They also suggested I keep copies of all my HSA contribution statements with my tax records in case of an audit. Having that direct IRS guidance gave me peace of mind that I was handling the situation correctly.

Everyone's focusing on the W2 correction, but I want to point out something important about HSA contribution limits. For 2025, the limit is $4,150 for individual coverage and $8,300 for family coverage (plus $1,000 catch-up if you're 55+). Make sure you're not exceeding these limits when you add up BOTH your contributions AND your employer's. The IRS treats excess contributions pretty harshly - there's a 6% excise tax on amounts over the limit for each year they remain in your account. So while fixing the W2 reporting is important, also double check that you're not over-contributing when you combine both sources!

Quick tip from someone who dealt with this exact issue: If your employer refuses to issue corrected W-2s, you can actually file Form 8889 (Health Savings Accounts) correctly regardless of what your W-2 says. Line 2 of Form 8889 asks for employer contributions to your HSA, which you should fill out accurately even if Box 12W on your W-2 is wrong. This form becomes part of your tax return and shows the IRS the correct contribution amounts. I've done this for two tax years without any issues. Just keep your HSA statements showing all contributions as backup documentation.