Article Two, Section 1, Clause 5 of the United States Constitution, states:
No person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty-five Years, and been fourteen Years a Resident within the United States.
This being true, each individual state has its own requirements for who gets on ballots in that state. As long as an individual state does not overrule constitutional requirements in Article 2 and the 14th Amendment's Equal Protection Clause, any other laws regarding eligibility requirements are reserved by the individual states.