The governor of Arizona makes an appointment to fill the U.S. Senate vacancy, and the appointee serves until the next regularly-scheduled, statewide general election. The person elected at that next regularly-held general election serves for the remainder of the unexpired term, if any. If the term was set to expire at that general election, the person elected serves a full six-year term.
The governor's appointee must be of the same political party as that of the vacating Senator.