Q. do you know if I can still deduct them?
A. Yes, by filing an amended state tax return.
Q. if I can, is there a limit to the number of years I can go back here in New Mexico?
A. Yes. A refund must be claimed three years from the due date of the original tax year return, including valid filing extensions.
Reference: https://www.efile.com/how-to-amend-new-mexico-state-income-tax-return-form/
