What Is Transitional Kindergarten (TK)?
By First Cubby Editorial · Updated 2026-07-09
Transitional kindergarten (TK) is a free public-school grade — the first year of a two-year kindergarten program — for young 4-year-olds. It uses a play-based, developmentally appropriate curriculum to bridge preschool and kindergarten. In California, TK is now universal: every child who turns 4 by September 1 can attend free, regardless of income.
How TK works
TK is taught by credentialed teachers on a public elementary campus, with smaller adult-to-child ratios than kindergarten and a curriculum geared to younger learners — lots of hands-on, play-based learning alongside early literacy and math foundations. Children who complete TK then go on to kindergarten, so it’s a gentle two-year on-ramp rather than a repeated grade.
California’s universal TK
California phased in universal TK over several years. As of the 2025–26 school year, all children who turn 4 by September 1 are eligible — a big expansion from the old “young fives” window (children with fall birthdays). It’s free and voluntary. For the official rules, see the California Department of Education’s Universal PreKindergarten FAQ.
TK outside California
Statewide TK by that name is mainly a California program, but several other states run similar “young fives” or transitional programs under different names. Rules, ages, and availability vary a lot by state and even district — always confirm with your local school district.
TK, pre-K, or preschool?
They overlap. Compare them directly in TK vs. preschool, TK vs. kindergarten, and what pre-K is. For readiness, see kindergarten readiness and your 4-year-old.
Eligibility ages and program availability change and vary by state and district. This is general guidance — always confirm the current rules with your local school district.
Frequently asked questions
What is transitional kindergarten?
Transitional kindergarten (TK) is a free public-school grade that acts as the first year of a two-year kindergarten program. It uses a play-based, developmentally appropriate curriculum to bridge preschool and kindergarten for young children who aren’t quite old enough for kindergarten.
Who is eligible for TK in California?
As of the 2025–26 school year, California TK is universal: any child who turns 4 by September 1 is eligible, free of charge, regardless of income or background. Enrollment is voluntary.
Is transitional kindergarten free?
Yes. TK is part of the public school system, so it’s free for eligible families — one of the only universally free options in the year before kindergarten.
Is TK mandatory?
No. TK is optional. It’s offered free to eligible children, but families can choose preschool, another program, or to wait for kindergarten instead.
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