No, if you continue to not claim depreciation (see below), you will not pay any Federal taxes when you sell the house if it is sold within 3 years of you moving out of it.
However, claiming depreciation is not an option, it is a requirement of the law.
In your case, this probably won't affect you, but I'll say it for anybody else that may read this: Depreciation lowers your "basis" (cost) whether you claim it or not. So let's say the cost of the home and improvements were $200,000, and you COULD have claimed $15,000 of deprecation. Your "basis" (cost) is now $185,000, even if you did not claim the depreciation. So if you sold the house for $240,000 (after selling expenses), you now have a $55,000 gain.
The $250,000/$500,000 exclusion for using the home as your Principal Residence for 2 out of the last 5 years does NOT eliminate depreciation, so in most cases you would pay tax on it when the house is sold. However, in your case, because you did not actually claim the depreciation, that exclusion CAN cover it.
If the home was sold for less than $185,000 (in the example), no, you would not pay any tax on the depreciation. In other words, you would have wasted $15,000 of deductions by not claiming the depreciation.
