Depending on where the check is from you can request the writer to reissue the check. You should also be able to deposit the check at your bank where they have recourse if a stop pay has been issued.

most checks say when they expire right on the check...YDI

I am sorry for you about the timing. But frankly YDI - I thought everyone knew that checks have an expiration date. In the future, if you have a big slug of money you want to hold for an emergency, cash it and put it into a savings account at a bank or credit union. It will be safe there. In the meanwhile, contact whoever the check was from and explain what happened and ask if they can give you a new check. They are probably not legally obligated to do so but they might to help you out. But don’t expect too much sympathy - Most of us with checking accounts balance our accounts monthly and a long outstanding check is a headache to keep track of properly so your holding the check a long time caused extra work. And many banks charge a fee for canceling a check, which is what most individuals do after a couple of months.

I forgot my grandpa gave me a check at my son's baby shower.. found it when he was 18 months and I was going through things in his room. yep did it to my self and cried but it happens. see if the place will reissue it otherwise you don't have a choice. most are 60 to 90 days after issue date.