There were once so many children at Frisha Moore’s Elk Grove preschool that families filled up the waitlist. Now, one of her playgrounds and two classrooms sit empty because one key group of kids has stopped coming.

Dozens of families in recent years have opted not to enroll their 4-year-olds at Moore Learning Preschool & Child Care Center, she said. Instead, they’re putting their children in transitional kindergarten, California’s new public pre-kindergarten grade.

Even though she provides a full day of preschool, compared with transitional kindergarten that lasts only about 3.5 hours, Moore can’t compete: Public school is free. She hasn’t broken even in months and thinks about closing the preschool, “every single day.” That would remove 91 licensed child care spots from the county, including 20 for children under age 2, for whom child care options are particularly scarce.

Transitional kindergarten’s expansion is one of Gov. Gavin Newsom’s signature educational achievements and a key part of his legacy on how California cares for its youngest residents.