My knowledge of taxes is largely based on learning how to explain what happens/happened for regular people. (writing an article for a newsletter or such.)
When property assessments are made, they can be made for whatever they think is market value; however, unless the home has had some major upgrade within the last year, there is a percentage limit to what can actually be taxed upon. The remainder of the increase is factored in over the next 2 or 3 years, usually.
2016 is about when home values in DFW exploded. Literally. Toyota and other large corporations moving into the area changed the market overnight. At the time, one of my “zone out and kill time” activities was logging into Trulia and looking at listings. Neighborhoods with houses that had been in the 250,000 range zoomed to 450,000-500,000 overnight. No doubt that affected more rural properties as well. The market has (oddly) remained at the crazy level, unlike the past two crazy property inflations since I bought my house in 1984. (Bought at 45,500 when rate were at 13%. I got “lucky” and qualified for a 10% loan. Then the S&L crisis happened. My house value went to something like 21,000. It inched back up over the years, and got as high as 80,000. Then the next real estate crash. And value back down to about 48,000. Now, it has inched (and zoomed) its’ way up to 153,000. But my taxable value is significantly less, due to the caps on annual increases.
If you are 65 or older, the Senior Citizen exemption is well worth your time. Depending on where you live, it caps your tax rate/property value at whatever is in place at the time you turn 65. Some people use the term “freeze” - but that’s not accurate; if the local tax rate or the valuation goes down below the level yours were capped, your taxes will go down accordingly. They just cannot go over the rate in place when you turned 65.
Step one of contesting appraisal is not missing the deadline to do so. Oops.