How long must you have been a US citizen to be President?

You have to be at least 35 years of age and you must have been born on US soil. In other Words, you must have been a citizen since birth.

The source of this thresh-hold requirement is Article II, Section 1, Clause V of the Constitution of the United States of America. To view a transcript of the Constitution of the United States of America, available on the website of the national archives, please feel free to click on the hypertext link listed below under Related Links.

Article II, Section 1, Clause V (mentioned above) does NOT state that you have to be born on U.S. soil. It only states that you must be "a natural born Citizen, or a Citizen of the United States..." This means that if your parents are/were U.S. citizens and you were born abroad, you are still eligible to become the U.S. president.