County General is becoming a veritable full house.

John Stamos has signed on as a series regular on ER, reprising the role he tried out during a guest stint on the NBC show last fall.

Stamos had been in negotiations for the past month to make his full-time return as Tony Gates, a flirtatious med school student-paramedic who also happens to be a Gulf War vet. According to E! Online TV columnist Kristin Veitch, the hitch was the up-in-the-air status of Stamos' ABC sitcom, Jake in Progress.