Dear County and District Superintendents, Charter School Administrators, and School Principals:

New Definition of Developmentally Appropriate Curriculum in Transitional Kindergarten

This letter is to notify you that Education Code Section 48000[d] was amended on July 9, 2026, to clarify what a developmentally appropriate curriculum is for transitional kindergarten (TK). Under the previous definition, TK must use a “modified kindergarten curriculum that is age and developmentally appropriate.” In the updated language, “modified kindergarten” was removed because that caused confusion in implementation, and “age and developmentally appropriate” is now further detailed as the following:

• Instructional practices that promote child development and learning through a strengths‑ and play-based approach to joyful, engaged learning that address the domains of development in the department’s Preschool/Transitional Kindergarten Learning Foundations (PTKLF).
• A cohesive set of principles, learning goals, intentional teaching strategies, activities, experiences, environments, and materials designed to help children learn and thrive in ways that are appropriate to their age and stage of cognitive, social, emotional, and physical development, as well as their individual needs, home language(s), and cultural experiences.

I am happy to report that, since the expansion of TK to serve younger four-year-old children, TK programs have increasingly adopted more developmentally appropriate, play-based curriculum—as evidenced in information you all have shared through the Universal PreKindergarten (UPK) Planning and Implementation Grant reporting. As a result, this new definition better aligns with the direction TK programs have already been working to implement as they continue to expand.

The California Department of Education (CDE) has several resources and tools to support TK programs in implementing age- and developmentally appropriate curriculum and instructional practices aligned to the PTKLF, including the following:

• UPK Curriculum and Evaluation Toolkit, which includes a self-evaluation tool for assessing your TK program’s curriculum, including administrator checklists for each curriculum area. This can be accessed at https://www.caeducatorstogether.org/resources/220753/upk-curriculum-toolkit.
• UPK Curriculum Guidance, which is a less exhaustive and shorter-form checklist of elements to consider in a curriculum and can be accessed at https://www.caeducatorstogether.org/resources/121676/upk-curriculum-checklist.
• Preschool Through Third Grade Learning Progressions, which demonstrate developmentally appropriate practices across the P–3 continuum and can be accessed at https://www.cde.ca.gov/ci/gs/p3.
• The Desired Results Developmental Profile (2025) observational assessment, which helps educators assess students’ individual needs across a range of cognitive, social, emotional, and physical development domains. The assessment for TK can be accessed at https://www.desiredresults.us/sites/default/files/docs/drdp%202025/DRDP%20(2025)%20PTK%20View_04202026_ADA.pdf.
• Sample TK schedules, which note various contexts and activity lengths that are developmentally appropriate for students (and are inclusive of rest and outdoor time). This schedule can be accessed at https://cauniversalprek.org/resource/sample-tk-full-day.
• The Powerful Role of Play in Early Education, which provides an in-depth look at play-based approaches and can be accessed at https://cauniversalprek.org/resource/the-powerful-role-of-play-in-early-education.
• The California Literacy Roadmap, which provides instructional guidance inclusive of TK for literacy and biliteracy and English-medium and multilingual program settings, can be accessed at https://www.cde.ca.gov/ci/cl/index.asp?tabsection=3.

The CDE also partnered with the National Association for the Education of Young Children to develop a short principal checklist on what to look for in a TK classroom to ensure the curriculum and instructional practices are age- and developmentally appropriate. To access this resource, visit https://www.naeyc.org/resources/topics/dap and scroll down to the “DAP Book Study Guides and Checklists” to access the “DAP Checklist for Principals”. To stay up to date on additional resources, please subscribe to the Department’s P–3 listserv by emailing “subscribe” to subscribe-cdep3updates@mlist.cde.ca.gov.

The state’s instructional materials adoption process also reflects this emphasis on developmentally appropriate practice, as TK is included in the 2026 California English Language Arts/English Language Development (ELA/ELD) Instructional Materials Follow-Up Adoption process. The Evaluation Criteria Maps for TK programs (Program Types 6.1, 6.2, and 6.3) are aligned to the PTKLF (TK Foundations Maps) and include several items related to developmentally appropriate practice. For example, the 2026 ELA/ELD Instructional Materials Follow-Up Adoption Supplemental guidance states that the materials submitted under Program Types 6.1, 6.2, and 6.3 must demonstrate developmentally appropriate design, with limited use of worksheets or workbooks, and emphasis on playful, child-directed learning. On November 18–19, 2026, the State Board of Education (SBE) will take action on program adoption recommendations from the Instructional Quality Commission. As such, adopted recommendations by the SBE for TK will also align with the clarified definition of age- and developmentally appropriate curriculum in statute. For more information on adopted instructional materials, visit the CDE Instructional Materials web page at https://www.cde.ca.gov/ci/rl/im.

If you have any questions about this new definition and any guidance that is or will be developed, please contact our Early Education Division at UPK@cde.ca.gov.

Sincerely,

Tony Thurmond
State Superintendent of Public Instruction