Every state (and DC) has their own way to handle them, on whatever lines they have on whatever forms they use...so i's all over the place.
...I don't know DC forms....maybe someone who knows DC will see this and suggest where they are on teh DC forms...or look yourself by going to the DC tax department page, save PDF copies of their 2019 tax forms and instructions, and search for the place they put them...usually a subtraction section.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
