Can a 16-year-old move out and live with her boyfriend without parental permission?
Yes, you can do that. But, depending on what state you live in your parents may be able to make you come back home or worse have you placed in a juvenile offenders facility. Also, your boyfriend may be arrested for statutory rape unless you live in a state in which the age of consent is below 16. On July 4, 2006 South Carolina's age of conscent was lowered to 14 years old. Check your state laws to make sure you or your boyfriend don't end up being arrested. No, the age of majority for most US states is 18, in a few states it is higher. The age of majority and the age of consent are two entirely different laws and therefore are applied differently. A 16-year-old is under the custody or his or her parents until they reach the age of majority in the state in which they reside or until a court rules otherwise. FYI, South Carolina has never lowered the AOC. The law stating the AOC to be 14, is "hard coded" into the state's Constitution in 1999, that law is overridden by amendment SCC 16-15-140 which sets the AOC at 16 for both genders.
If you are sixteen and pregnant and do not have parent permission to marry your eighteen year old boyfriend is there a state where they will marry you?
You need to be worried about the laws of your state. Boyfriend can't take you to another state to get married. First, it's illegal to take a minor across state lines without parental permission. Second, even if it wasn't, you couldn't get married anyway, because you're a minor without parental permission who is not a resident of their state.