While working at 2 different companies in 2020, I contributed excess (about $2000) to my 401k. I informed one employer and the company managing that 401k. My employer says the 401k company will issue me a 1099-R form and refund, but my employer will not issue a corrected W-2. My understanding was since I caught the overcontribution before filing my 2020 taxes, my employer can correct my W-2. With a corrected W-2 my total retirement plan contributions between the 2 plans will not exceed the $19,500 limit, I won't be penalized for an early withdrawal from my 401k, and those contributions won't be taxed twice (between this and next year). Is this understanding correct? Should my employer issue a corrected W-2 or is a 1099-R sufficient? If the W2 is the better option, are they obligated to make the correction?
Additional information:
I made contributions to both a Roth and pre-tax 401k (about 30/70 split between plans respectively).
I'm below the eligibility ages for 401k withdrawal or catch-up contributions.
