Can you please clarify? What state are you filing taxes for? Is your retirement benefit your only income? Is your retirement benefit from the state you're living in?
i.e. if you have other income, you may still be required to file.
AND
I think a couple states require you to file their state as long as you have to file Federal forms......then, int eh actual state forms, whatever state exemption is available....that is applied, and if you don't owe state, you still have to file it to prove you don't owe them anything.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*