California Implements Transitional Kindergarten with Some Success, Variation in Approaches

San Mateo, Calif. – A study looking at the first-year implementation of transitional kindergarten in California finds that most school districts provided the new grade level, and that approaches varied widely. The results, which are shared in a new report by the American Institutes for Research (AIR), found that transitional kindergarten appears to provide a different experience than traditional kindergarten, one more appropriate for young learners.

California established the program under the Kindergarten Readiness Act of 2010, which changed the kindergarten entry age so that children must turn 5 by September instead of December to enroll. The new grade level was put into place to promote school readiness for California’s youngest learners who, prior to the law, would have enrolled in kindergarten at age 4. Before the act, California was one of only a few states to allow four-year-olds to enroll in kindergarten.

The study collected data from focus groups, interviews, surveys and classroom observations. Other notable findings from the analysis include:

  • Overall, 89 percent of districts provided transitional kindergarten in its first year, 2012-13. More districts provided full-day (58 percent) than half-day (41 percent) programs. Small- to medium-sized districts—those with fewer than 350 kindergartners—had more full-day classrooms (69 percent) than large districts (42 percent).
  • Transitional kindergarten students were similar to kindergarten students in gender, ethnicity, free or reduced-price lunch eligibility, and English learner status, indicating that groups of students were not disproportionately left out of the program.
  • Ninety-five percent of transitional kindergarten teachers had early education teaching experience, having taught preschool, kindergarten or first grade. Teachers who taught kindergarten before the program was implemented represented the largest group (87 percent).
  • While teachers were experienced, they reported having attended few professional development sessions focused on transitional kindergarten. Teachers, on average, received 11 hours of such preparation in the first year, but many did not receive any professional development specifically on transitional kindergarten.
  • Some districts served transitional and regular kindergarten students in combination classrooms. Classrooms that included only transitional kindergarten students were more likely to focus on social-emotional instruction and use child-directed activities than combination classrooms. 
  • There was substantial variability in how districts approached implementation of the new grade level, including variation in the curricula teachers used to guide classroom instruction.
  • The most common challenges reported by districts implementing transitional kindergarten were funding, developing a transitional kindergarten report card, selecting curricula for the new grade level, and providing professional development for teachers.
  • Parents participating in focus groups were pleased with the program overall and said they felt their children were benefiting from the additional support prior to kindergarten.

The report also includes recommendations for the development of transitional kindergarten. For example, the authors emphasize the importance of providing more training for teachers and expanding outreach to parents.

This report is a second in a series highlighting findings from the study, which is supported by the Heising-Simons Foundation and the David and Lucile Packard Foundation. The first paper offered an initial look of the number of districts who enrolled transitional kindergarten students, and how they approached implementation. The next phase of the study, now underway, is examining the impact of the program on students’ preparedness for kindergarten.

To read the full report, visit

About AIR
Established in 1946, with headquarters in Washington, D.C., the American Institutes for Research (AIR) is a nonpartisan, not-for-profit organization that conducts behavioral and social science research and delivers technical assistance both domestically and internationally in the areas of health, education, and workforce productivity. For more information, visit


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