In California, pre-K typically serves children ages 3 and 4, but the exact age depends on which program you’re looking at. The biggest development is Universal Transitional Kindergarten (UTK), a free public program now available to all four-year-olds. Other options, including state preschool and Head Start, serve children as young as 3, and licensed private preschools can accept children starting at age 2.
Transitional Kindergarten: Now Open to All Four-Year-Olds
Transitional Kindergarten (TK) is California’s free, public pre-K program run through the public school system. Starting in the 2025-26 school year, every child who turns four by September 1 of that school year is eligible to enroll, regardless of family income, zip code, or immigration status. This is the result of a 2021 law that phased in Universal TK over several years, with full access arriving in 2025-26.
Before the expansion, TK had a much narrower window. It originally served only children whose fifth birthday fell between September 2 and December 2, essentially kids who just missed the kindergarten cutoff. That eligibility still applies as well, so children in that birthday range continue to qualify. But the universal expansion is the bigger story: if your child will be four by September 1, they can attend TK at your local public school for free.
TK uses a modified kindergarten curriculum designed for younger learners. It’s a full school-day program, though hours vary by district. Because it runs through the public school system, you enroll through your local school district the same way you would for kindergarten.
California State Preschool Program: Ages 3 to 5
The California State Preschool Program (CSPP) is a state-funded option for children ages 3 and 4 (and in some cases 5, if they haven’t yet entered kindergarten). It’s designed to help children from lower-income families transition smoothly into kindergarten. Unlike TK, CSPP has income requirements, so not every family qualifies.
CSPP programs are offered at public schools, community centers, and child care agencies across the state. Some operate part-day schedules while others offer full-day care. If your child is 3 and you’re looking for a pre-K option before they’re old enough for TK, CSPP is worth checking into. Contact your local school district or county office of education to find programs near you and confirm income eligibility.
Head Start: Birth Through Age 5
Head Start is a federally funded program that serves children from birth through age 5 whose families earn below the federal poverty level. Families receiving public assistance like TANF or SSI also qualify, and foster children are eligible regardless of their foster family’s income. Children from families experiencing homelessness qualify as well.
Head Start programs vary in structure. Some focus on preschool-age children (3 and 4), while Early Head Start serves infants and toddlers. Both are free. You can search for local Head Start programs through the federal Head Start website or by contacting your county’s resource and referral agency.
Private Preschools: Starting at Age 2
Private preschools in California operate under state licensing rules that allow them to serve children as young as 24 months (2 years old) through first-grade entry age. In practice, most private pre-K programs enroll children starting at 2.5 or 3, depending on the school’s own policies and whether the child meets developmental milestones like potty training.
Private programs set their own tuition, schedules, and curricula. Some follow a play-based approach, others are more academic, and many blend both. Costs vary widely depending on location, hours, and the program’s structure. If your child is younger than 4 and you don’t qualify for income-based programs, private preschool is the main option until they’re old enough for TK.
Quick Age Breakdown by Program
- Transitional Kindergarten (TK): children turning 4 by September 1 of the school year (free, public)
- California State Preschool (CSPP): ages 3 to 5 (free, income-based eligibility)
- Head Start: birth through age 5 (free, income-based eligibility)
- Private preschool: as young as 2, depending on the school (tuition-based)
For most families, the practical answer is that your child can start free public pre-K at age 4 through Transitional Kindergarten, and if you need earlier enrollment or your child is 3, state preschool, Head Start, or private programs fill the gap.