### Question
How is the "period of nonqualified use" defined?


### Answer
The term **period of nonqualified use** is defined in *26 U.S.C. § 121* as follows -

> any period (other than the portion of any period preceding January 1, 2009) during which the property is not used as the principal residence of the taxpayer or the taxpayer's spouse or former spouse

#### Citation:
  - *26 U.S.C. § 121*
  - Heading: **Subtitle A-Income Taxes > CHAPTER 1-NORMAL TAXES AND SURTAXES > Subchapter B-Computation of Taxable Income > PART III-ITEMS SPECIFICALLY EXCLUDED FROM GROSS INCOME**

