If you've not filed one, your property taxes will increase to the pre-exempted rates. Call your county assessor's office and see if they have your exemption on file, verify the date it was filed and ask if it needs to be renewed. That should take care of it.
I just closed on my refi this week. Yes, Indy_Guy_77 is right, I have to fill out another homestead credit form to get the credit for 2013, or my rate will go up.
In Marion Co, you have to call and ask, or go to the Auditors office at the City County Building. Their number is 327-3001, M-F, 8-4:30. They will immediately transfer you and after a few min on hold you will be able to talk to someone who will look up the status of your exemption by either address or parcel number. I just did it yesterday, turned out I was ok.