Question: how is 401k reported on w2?
Answer: Generally, contributions to your 401(k) or TSP plan will show up in box 12 of your W-2 form, with the letter code D. You can get to the W-2 section in TurboTax by searching for W-2 (upper- or lower-case, with or without the dash) and then clicking the Jump to W-2 link in the search results.