The 9% company match is immaterial to you.
IF all you entered was your W-2 data and the box 12 code D $$, there should be no complaint (well, at least that is the case with my desktop software). For 401k contributions thru your employer, as long as the particular 401k plan allows it, you are allowed to contribute to the 401k beyond age 70.5 and no RMD distributions are required until you leave employment there.
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So, unless it's an online software bug, I can't see that the software would target that.
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BUT...you also said you rolled over your old plan (into an IRA???). Those $$ would be subject to RMDs if you turned 70.5 in 2019. You do have to make those RMDs are taken if they went into an IRA
(....and depending on when you rolled them, you might have been required to keep the RMD at the time you rolled.....but I'm hazy on the procedures and timing of that....may depend on what year you rolled them.)
I don't see how those would show up in any way as an excess contribution to your 401k though....shoudl not be related at all (I think)
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I just tried an Online W-2 with 10,000 in box 12, code D for a 75 year old....and the software says nothing about an over contribution when I go thru the the full interview and Federal review/error check. So I think the Online software is operating OK too. At least from what I can gather about yoru description
But again...are you sure you did NOT enter anything on the Deductions & Credits page for "Traditional and Roth IRA Contributions". That would have triggered an over contribution warning.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
