Box 12 of W2 shows AA with $1100, but I contributed $1900 to retirement - Why the discrepancy?

The discrepancy you're seeing is actually pretty common. Box 12 code AA on your W-2 specifically shows your elective deferrals to a 401(k) plan - meaning only the money YOU chose to contribute from your salary, not what your employer added. Your retirement account statement typically shows the total contributions to your account, which often includes both your elective deferrals AND your employer's matching contributions or other employer contributions. This would explain why your statement shows $1900 while your W-2 Box 12 shows only $1100. To verify this, check your final paystub from 2023 - it should show your total 401(k) contributions for the year, which should match the AA amount on your W-2. Also, your retirement account statement might break down the contributions between employee (your) contributions and employer contributions if you look at the details.

Don't panic, but you should definitely file an amended return (Form 1040-X) to correct your filing status from Head of Household to Single. The IRS can and does check eligibility for filing statuses, and filing incorrectly as HoH when you're not eligible could lead to issues. Since you caught this early and it was an honest mistake, filing an amended return promptly will likely help you avoid any serious penalties. The IRS generally appreciates taxpayers who self-correct. You'll need to recalculate your tax liability based on the Single filing status, which typically results in owing more tax since HoH has more favorable tax brackets. If your amended return shows you owe additional tax, you should pay that amount as soon as possible to minimize any interest or penalties that might accrue. The good news is that amending soon after filing shows good faith on your part.

After struggling with exactly this same W-2 Box 12 issue last year where my AA code amount didn't match what I thought I contributed, I found this amazing tool called taxr.ai (https://taxr.ai) that saved me tons of headache. It's like having a tax expert look over your documents without the massive bill. I just uploaded my W-2 and retirement account statement, and it immediately flagged the discrepancy and explained why they were different - turns out my statement was including employer matching AND some gains in the account! Would have spent hours on hold with HR trying to figure this out otherwise.

I had almost the exact same thing happen to me last tax season and was freaking out! I uploaded my return to https://taxr.ai and it immediately flagged that I didn't qualify for HoH status and explained exactly why. It even helped me understand what I'd owe after amending to single status. The tool actually walked me through the whole amended return process and showed me which forms to file. Super helpful because I was completely lost trying to figure out how to fix my mistake. It also explained what penalties I might face and how to request a waiver based on it being an honest misunderstanding.

Just wanted to update everyone - I tried taxr.ai after seeing the recommendation here and it was incredibly helpful! Had the same issue with my retirement contributions on my W-2 (Box 12 code AA) not matching my statements. Uploaded both documents and within minutes it explained that my statement included both my contributions AND my employer's 3% match, plus some interest earned during the year. The platform actually broke down the numbers for me: my $2350 contribution (shown on statement) minus employer match of $705 minus interest earned of $218 equaled the $1427 that appeared in Box 12 AA. Mystery solved! Definitely bookmarking this for next tax season.

Thank you everyone for the recommendations! I tried taxr.ai after seeing it mentioned here and it was incredibly helpful for my incorrect filing status situation. It confirmed I definitely didn't qualify for Head of Household and showed me exactly why - apparently you need a qualifying person who lived with you AND you paid more than half the cost of keeping up the home. It calculated I'll owe an additional $1,842 by filing as Single instead of HoH and generated a detailed explanation I could include with my amended return explaining the honest mistake. The system even flagged that I might qualify for First Time Penalty Abatement and included language I could use to request this from the IRS. Already working on my 1040-X!

If you need to double check this with the actual IRS, good luck getting through to them! After 4 attempts and hours of waiting, I discovered Claimyr (https://claimyr.com) and it changed everything. They have this system where they wait on hold with the IRS for you and call you when an agent is ready to talk. You can see how it works here: https://youtu.be/_kiP6q8DX5c I had a similar W-2 Box 12 code issue and needed to verify whether I needed to file a correction. Got through to an actual IRS agent in record time who confirmed everything was reported correctly. Huge relief!

After struggling to reach the IRS for WEEKS to ask about fixing my incorrectly filed return (also used wrong filing status), I found Claimyr (https://claimyr.com) and it was a lifesaver. They have this service that waits on hold with the IRS for you and then calls when an agent is ready to talk. Check out how it works: https://youtu.be/_kiP6q8DX5c Got to speak with an actual IRS representative who walked me through the whole amendment process and confirmed I could request penalty abatement as a first-time offender. She even gave me the specific form codes to reference. Before Claimyr I kept getting disconnected after waiting on hold for 2+ hours!

I need to eat my words about Claimyr! After posting my skeptical comment, I decided to try it myself since I've been trying to reach the IRS about retirement contribution coding issues on my W-2 for weeks. What shocked me is that they actually got through to an IRS representative in about 70 minutes! I didn't have to wait on hold at all - just got a call when the agent was ready. The IRS agent confirmed that my Box 12 AA amount should only reflect MY contributions, not my employer's match, which explained the discrepancy I was seeing. If you're struggling to get answers directly from the IRS about your tax documents (which let's face it, who isn't?), this service is absolutely worth it.

I was completely skeptical about Claimyr but after my third failed attempt to reach the IRS about my filing status mistake, I decided to try it. I'm shocked to report it actually worked perfectly! They got through to an IRS agent in about 55 minutes (I had been trying for days), and I was able to speak directly with someone who confirmed exactly what I needed to do to amend my incorrectly filed HoH return. The agent even noted on my account that I had called proactively to fix the issue, which she said would help if there were any questions later. If you need actual IRS guidance on fixing a tax mistake, this service is absolutely worth it. No more waiting on hold for hours only to get disconnected!

Another thing to check: does your company offer both traditional 401k AND Roth 401k options? If you contributed to both, the Roth contributions would show up under code AA in Box 12, while traditional contributions would be under a different code. That could explain the difference.

You might be eligible for Head of Household even without children! Do you provide more than half the support for a parent? Or did you have a qualifying dependent who doesn't live with you due to school, illness, or other temporary absence? Don't automatically assume you don't qualify.

Has anyone looked at whether the $1900 statement value might include earnings/growth? My retirement statements always show contributions + earnings for the period, and that threw me off big time last year.