Well, technically that's not exactly true. You have to OWN the house for two more years in order to avoid the tax, but you don't have to continue living there. Again, the 2 years of ownership and 2 years of residence (within the 5 years preceding the sale) do not have to be the same 2 years. If you move out, and 2 years from now you sell the house, you will still have lived there for 2 years out of the 5 years preceding the sale, even though it's not the last 2 years prior to the sale.
This can get very complicated. You might want to read up on all the rules in IRS Publication 523, Selling Your Home, which you can download from the following link.
<a rel="nofollow" target="_blank" href="
https://www.irs.gov/pub/irs-pdf/p523.pdf">https://www.irs.gov/pub/irs-pdf/p523.pdf</a>
