### Question
What is the definition of taxable year?


### Answer
The definition of **taxable year** is as follows in *26 U.S.C. § 21*:

> the taxable year of the taxpayer in which the service is performed

#### Citation:
  - *26 U.S.C. § 21*
  - Heading: **Subtitle A-Income Taxes > CHAPTER 1-NORMAL TAXES AND SURTAXES > Subchapter A-Determination of Tax Liability > PART IV-CREDITS AGAINST TAX > Subpart A-Nonrefundable Personal Credits**

