Lesson learned on the subject - I bought a few acres next to my property that has an ag use exemption. The property I bought never had it. Five years ago I applied to have an exemption applied to the additional acres I bought. The justification is that cows can graze the property as there is no fence between the two different tracts. Anyway, a called the appraisal district and asked about the status of the exemption and they said that while I had waited the requisite 5 years, I had to re-apply for the exemption to kick in. So if you are going through the waiting period, don't assume that when the waiting period requirement has been met that the appraisal district will automatically provide the exemption. You must re-apply.