U.S. government vs US Government

U.S. government and US Government both are nouns.

Word	Noun	Adjective	Verb	Adverb
U.S. government	Yes	No	No	No
US Government	Yes	No	No	No

As nouns, U.S. government and US Government are synonyms defined as:

U.S. government and US Government: the executive and legislative and judicial branches of the federal government of the United States

Other synonyms of U.S. government include U.S., United States, United States government.

U.S. government (noun)	US Government (noun)
the executive and legislative and judicial branches of the federal government of the United States	the executive and legislative and judicial branches of the federal government of the United States