Can anyone explain what the code in box 12 on my W-2 means?

So do I need to enter all the box 12 codes somewhere on my tax return? Mine has code D with about $4,500 next to it. Is that going to affect my refund?

The good news is that most tax software will guide you through what to do with these codes. For code D specifically, that's your 401(k) contributions which are already excluded from your taxable wages in box 1. You don't need to do anything special with this on your return - it's already been accounted for in your W-2 box 1 wages. The amount shows how much you contributed to your retirement account pre-tax, which is good information to have. It helps explain why your box 1 wages are lower than your gross pay.

Does it actually work with all the different box 12 codes? I've got a W for HSA contributions and a DD for health insurance and I'm not sure what to do with either of them.

I'm always skeptical of these tools. Does it actually explain things in a way that's helpful or just regurgitate the IRS definitions? And what about privacy - is it secure to upload my W-2 with all my personal info?

It worked perfectly with all my codes - it recognized my code D for 401(k), code W for HSA contributions, and even explained the weird code DD that shows employer health insurance costs. It doesn't just give definitions but explains how each one impacts your taxes and what you need to do with that information. As for security, they use bank-level encryption and don't store your documents after processing. I was concerned about that too but they explain their security practices on their site. I felt way more comfortable using this than sending my docs to some random person online.

Wait, how does this actually work? Does it just call the IRS for you or what? I'm confused how a service can get you through when nobody else can.

Sounds like a scam to me. The IRS phone system is designed to be impossible - no way some random service can magically get you through when millions of people can't. What's the catch here?

It doesn't just call for you - they have some technology that navigates the IRS phone tree and waits on hold in your place. When they actually reach a human agent, you get a call to connect with them. It saved me literally hours of hold time and frustration. No catch that I found - it works exactly as advertised. I was skeptical too but after trying to call the IRS myself multiple times with no success, I was desperate. The service just makes the calls and handles the waiting so you don't have to. When they reach an agent, you get the call to talk directly to the IRS person.

What about code C? That's what's on mine and I can't find a straight answer on Google.

Code C on your W-2 represents taxable cost of group-term life insurance over $50,000. Basically, if your employer provides you with life insurance coverage that exceeds $50,000, the cost of that excess coverage is considered a taxable benefit. The amount shown with code C is already included in your taxable wages in boxes 1, 3, and 5 of your W-2, so you don't need to do anything additional with this amount when filing. It's just explaining why your taxable wages might be higher than you expected.

Code G represents 457(b) retirement plan contributions, which is a type of deferred compensation plan often used by state and local government employees. For most states, these contributions are treated the same way as they are for federal taxes - they're already excluded from your taxable wages. But a few states might treat these differently. Which state are you in? Some states don't fully recognize all federal tax deferrals.