Transitional Kindergarten (TK): What It Is, Who Qualifies & TK vs. Preschool (2026)
By First Cubby Editorial · Updated 2026-08-20
Transitional kindergarten (TK) is a free, public grade in California for young children in the year before kindergarten. It’s the first year of a two-year kindergarten program — taught by credentialed teachers in a public school, with a play-based, developmentally appropriate version of the kindergarten curriculum. Under “universal TK,” California is making it available to all 4-year-olds by the 2025–26 school year.
TK vs. preschool vs. kindergarten
| Preschool | Transitional kindergarten | Kindergarten | |
|---|---|---|---|
| Who runs it | Mostly private programs (plus state pre-K & Head Start) | Public school districts | Public school districts |
| Cost | Usually tuition-based | Free | Free |
| Ages | ~2–5 years | The year before kindergarten (4–year‑olds under universal TK) | 5–6 years |
| Teacher | Early-childhood staff | Credentialed teacher | Credentialed teacher |
| Required? | No | No (optional) | Not until age 6 |
Who qualifies for TK in California
California has phased in TK over several years, widening the birthday window each time. By the 2025–26 school year it becomes universal — open to every child who turns 4 by September 1. Because the cutoff moved during the rollout, and some districts enroll younger “expansion” children, confirm the current eligibility date with your own school district before you plan around it. TK is offered by districts, so you enroll through your local public school — not through a private preschool — usually in the spring before the school year starts.
Is TK the same as preschool?
No — and the difference matters for your budget and your plan. TK is free public school for one specific year; preschool is generally a private, tuition-based program that can start as early as age 2. Many families do both in sequence: a year or two of preschool, then TK, then kindergarten. Preschool is not required before TK, but it’s a common way to build routines and social skills first. If you’re weighing the cost, our guides on how much preschool costs and how to afford preschool cover private tuition, state pre-K, and Head Start.
Preschool in California while you wait for TK
If your child isn’t TK-eligible yet, a preschool fills the earlier years. Browse programs, tuition, and licensing in California cities on First Cubby — for example Los Angeles, San Diego, San Jose, Oakland, Pasadena, and Sacramento — or see all cities. New to comparing programs? Start with how to choose a preschool and the questions to ask on a tour.
TK rules — especially the eligibility cutoff — are set by the state and change year to year during the universal-TK rollout. Always confirm the current details with your school district or the California Department of Education before enrolling.
Frequently asked questions
What is transitional kindergarten?
Transitional kindergarten (TK) is a free, public grade in California for young children in the year before kindergarten. It is the first year of a two-year kindergarten program, taught by credentialed teachers in a public school with an age-appropriate, play-based version of the kindergarten curriculum.
Is transitional kindergarten free?
Yes. TK is part of California’s public school system, so it is free to families, the same as kindergarten. It is offered by school districts, not by private preschools.
What is the difference between TK and preschool?
TK is a free public school grade for the single year before kindergarten, taught by a credentialed teacher and run by your school district. Preschool is usually a private, tuition-based program for ages roughly 2–5 (though free state pre-K and Head Start exist for families who qualify). Many children attend preschool first, then TK, then kindergarten — but preschool is not required before TK.
What is the difference between TK and kindergarten?
TK is the first of a two-year kindergarten experience: the curriculum covers similar areas as kindergarten but is adjusted to be more developmentally appropriate for younger children, with more play and hands-on learning. TK students move on to regular kindergarten the following year.
Who is eligible for transitional kindergarten in California?
California has been expanding TK eligibility every year, and by the 2025–26 school year TK is available to all children who turn 4 by September 1 (“universal TK”). Because the eligibility window has changed year to year during the rollout, confirm the exact birthday cutoff with your local school district before you enroll.
Is transitional kindergarten mandatory?
No. TK is optional — it is offered to eligible families but not required, and in California school is not compulsory until age 6. Families can choose TK, a preschool, or another arrangement for that year.
Do other states have transitional kindergarten?
TK as a formal, universal public grade is specific to California. Some other states and districts run similar “young fives” or pre-K bridge programs under different names, but they vary a lot — check your own state’s department of education or school district for what is offered.
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