How much would a $2500 529 deduction affect my MD State income tax refund?

[sunmi685]

I understand that I can get a deduction, and in terms of Federal taxes a deduction means roughly 1/3 back on my refund, is it roughly the same in a state deduction?

[SweetieJean]

 in terms of Federal taxes a deduction means roughly 1/3 back 

You cannot deduct 529 plan contributions on a Federal return.

https://www.irs.gov/uac/529-plans-questions-and-answers

The MD state deduction is worth whatever your marginal state tax rate is.

http://taxes.marylandtaxes.com/Individual_Taxes/Individual_Tax_Types/Income_Tax/Tax_Information/Tax_...