First, select the State Taxes tab.
Answer the Maryland interview questions that pertain to you and continue until reaching the page 'Here's the income that Maryland handles differently'.
Under the Education section, select start next to 'Maryland college Savings Plan Contributions'. Indicate 'yes' to one of the 529 plans offered and continue to indicate 'yes' if you made 2017 contributions. Then continue once more to enter your 529 contribution amount.
See attachments
I don't understand how the program can be correct. I'm entitled to a deduction of $25k (married couple with 5 beneficiaries) but when I input this amount, in the system, my MD tax liability increases by about $1000 vs. when I input a contribution amount of, say, $12,500. I spoke to a rep (not a tax expert) who was unable to explain this and generally was not helpful. I thought about upgrading for "expert tax advice" but the cost would be $100 (50 for federal and 50 for state) and I suspect the outcome would be equally unsatisfactory. At this point, I'm thinking I may have to do my taxes with a professional tax preparer/accountant to ensure I'm getting it right.
You want to see what the calculations are. First on the MD summary page ensure at the top of the page the $25K is showing for the Maryland College Savings Plan Contributions category.
1. Click "Tax Tools" in the left hand menu
2 Click "Tools" in the left hand menu
3 Click "View Tax Summary" in the center screen
4. Click "Preview my 1040" in the left hand menu
5 Click "MD Tax Summary" in the left hand menu
Verify the subtractions from income included the $25K or see what is there. This will help narrow down where the disconnect may be.