Why does DC D-40 show itemized on Line 17 but Line 18=$0? MFJ federal, MFS DC, Schedule A present with itemized, Schedule S SP deductions is forcing $0 on review.

[abethon]

We itemized federally and deductions (mortgage interest, etc.) appear on Schedule A . Using MFS on DC return, the allocation screen shows both spouses at $0's and issues an error if changed. This is leading to no deductions at all, which is not right.

[DaveF1006 · Accepted solution]

To resolve the $0 error on Line 18, you must manually allocate the expenses on the DC-specific screens (Schedule S):

1. Manually Split the Expenses: Navigate to the DC "Deduction Allocation" or "Schedule S" section. You must assign specific dollar amounts to each spouse. For example, if you both own the home, you might split the mortgage interest 50/50, or assign it to the spouse who actually paid the bill.

2. Watch the "SALT" Trap: DC does not allow a deduction for state and local income taxes, but it does allow a deduction for real estate taxes. If your federal Schedule A is mostly state income tax, your DC deduction will naturally be much lower than your federal one.

3. Check the "Itemized" Requirement: DC law states that if one spouse itemizes, the other must also itemize (they cannot take the standard deduction). If the software sees one spouse at $0 and the other trying to itemize, it may "zero out" both to force a correction.