SB Schools Offer Full-Day Kindergarten and Award-Winning Programs Online enrollment for kindergarten and transitional kindergarten (TK) in San Bernardino City Unified School District (SBCUSD) is underway. Children who will be five years old by September 1, 2026, are eligible to pre-enroll in kindergarten for the 2026–2027 school year. Transitional kindergarten is available for students who will turn five ...