Colton Harris-Moore entered the plea in federal court, reversing a not-guilty plea made last week. Harris-Moore's attorney said the 20-year-old could receive between 5 1/4 and 6 1/2 years in prison when he's sentenced in October.
Federal prosecutors were expected to give details of the plea deal reached with Harris-Moore's lawyers, but details were not released as of Friday afternoon.
The two sides had been negotiating whether Harris-Moore could participate in book or movie deals, with proceeds used to repay victims. His lawyers have said restitution could total about $1.3 million.
Authorities said Harris-Moore went on a two-year run from the law frequently stealing cars, boats and planes.
He earned the "Barefoot Bandit" nickname for allegedly committing some of the crimes without shoes.
He was captured in the Bahamas last July. In all, Harris-Moore is suspected of more than 70 crimes across nine states.
The Associated Press contributed to this report.