Form 8889 Part 1 line 3 is calculated incorrectly. Would like to know how to fix.
For 2025 I had a HDHP (necessary for an HSA) from Feb to Dec. I should be eligible for 11 months of HSA contributions unless the "Last-month rule" and it's "testing period" are passed which in my case, they aren't due to not having a HDHP the following 12 months.
I tell the software I had no coverage Jan, but no matter what I've said to the software, it's seemed to assume the Last-day rule and doesn't allow me to have line 3 on form 8889 be calculated for 11 months. On 8889 Part 1 line 3 it's telling me I can contribute the max $4,300 instead of instead of the correct 11 months of contributions at $3,941.67 (rounded on the 8889). Is there a way to fix this? I would love to be able to manually adjust line 3 to 3,942.
If you want to dive deeper into what I did with the software, if I answer Yes to "Were you an eligible individual for HSA contributions as of December 1, 2025?" which is correct in my case, the software doesn't ask me what months I was insured and I'm pretty certain it's assuming the Last-month rule. If I say no, it brings me to a page asking "Tell us about your monthly coverage" where it asks which months I'm specifically covered. I check not covered for Jan and self only covered for the other 11 months, but I still get the same outcome so it still must be assuming the Last-day rule. Funny enough writing all this, I just thought of way to finesse the software into the correct 8889. If I change Jan through Nov to covered and Dec to no coverage, the software can't assume the Last-day rule anymore and the correct 8889 is now generated where line 3 correctly says 3,942.
Ideally I would prefer to input all correct details into the software to be accurate. I don't like to mess around with the IRS. I'm not sure if inputting the wrong covered month to freetaxusa will matter though in terms of data on the 1040. If anyone knows how to fix this issue by entering the correct months (Feb to Dec), I'm still very interested in learning / knowing.