You can subtract the amount contributed to a qualified DC 529
College Savings Plan from your taxable income. The maximum amount you can deduct is $4,000 annually, and the contributions must be made to qualified college savings accounts you own. If you are married and file as Married Filing Jointly or Married Filing Separately - Combined Return, each spouse may deduct up to $4,000 for contributions made to all accounts for which that spouse is the sole owner.
A rollover distribution doesn't qualify as a contribution for this subtraction.
If you contributed more than $4,000 (or $8,000 for eligible joint filers) to one or more accounts, you can carry forward the excess (subject to the annual $4,000 limitation) for up to five years.
If you were a part-year DC resident during the tax year, you may deduct only the amount contributed when you resided in DC.