It truly depends on where you live, if asking for tax purposes. Mainly in the Northeast, they do assessments at least every 10 years, and your taxes can go up significantly at that time. If you are buying a new house, you should check when the house was reassessed, since it could be very soon, making the tax bill MUCH higher than advertised. In most other locations, tax assessments are tied to actual property values and change from year to year. I've lived in the same house for 5 years, and my tax assessment hasn't changed, but my taxes have gone up about 30% in the 5 years I have lived here. So assessment levels can have nothing to do with the rise of annual taxes, as much as the rising annual tax rate.