Culbreth, an American League umpire since 1999 and a veteran of two World Series umpire crews, allowed the Astros to replace a pitcher who hadn't pitched to a batter, which is a violation of rule 3.05 (b) of the MLB rule book.
Angels Manager Mike Scioscia argued but the umpire, with Culbreth as crew chief, let the pitchers' switch stand. Scioscia played the game under protest but the Angels won and the protest was nullified.
Culbreth's suspension will be served at a date to be determined by a Commissioner's Office, Major League Baseball said Friday. The other members of the crew -- Brian O'Nora, Bill Welke and Adrian Johnson -- were fined undisclosed amounts.