### Question
Can you define what United States tax means?


### Answer
**United States tax** is defined as the following in *26 CFR § 509.104*:

> the Federal income taxes, including surtaxes and excess profits taxes, and any other income or profits tax of a substantially similar character imposed by the United States after May 24, 1951

#### Citation:
  - *26 CFR § 509.104*
  - Heading: **PART 509—SWITZERLAND**

