I believe I have figured out what was causing the problem.
I did enter information into row 1d and that amount does display as a negative value on schedule 1 row 8s. The issue is that data from a previous return (I imported a past return into the 2024 version) was displaying in schedule 1 row 8z as a positive amount that exactly offset row 8s. This resulted in schedule 1 row 10 and row 8 on the income tax return to display as "0" rather than the negative amount listed on schedule 1 row 8s (and on the W2 box 12a).
Is it correct that there should be nothing displaying on schedule 1 row 8z based on the Medicaid waiver amount listed on the W2 box 12a?
