Mill Valley School District added 90 students in 2026-27, growing 3.9% while districts across Marin County lost enrollment.

The gain, reported in district enrollment data analyzed by the Mill Valley Briefing, pushed total enrollment from 2,326 in 2025-26 to 2,416 in 2026-27. Nearly all of it came from one grade: transitional kindergarten, where enrollment jumped from 174 students to 240, a 37.9% increase.

Every other elementary grade held roughly flat or shifted by single digits.

The TK surge was not spread evenly across the district's five elementary schools. Strawberry Point Elementary saw the largest jump, growing from 56 TK students to 80. Edna Maguire Elementary and Tamalpais Valley Elementary each grew from 40 to 60. Park Elementary added just two TK students, moving from 38 to 40. Old Mill Elementary does not offer a TK program.

The district expanded TK to 12 classrooms for the 2026-27 year, according to the Marin Independent Journal. That expansion came with a price tag: Tamalpais Union High School District Trustee Jenny Holden said in July that Mill Valley faced more than $2 million in costs to add a full TK grade, according to Enjoy Mill Valley.

California expanded TK eligibility to all 4-year-olds starting in 2025-26 under a phased rollout. The 2026-27 year is the second of universal eligibility, covering children who turn four by Sept. 1, 2026.

Superintendent Dr. Elizabeth Kaufman, now in her fourth year leading the district, said in August that the district had "tremendous momentum" heading into the school year.

The growth stands in sharp contrast to the Tamalpais Union High School District, which serves Mill Valley's high schoolers. TUHSD Assistant Superintendent Corbett Elsen said in July that the district projected "declining enrollment for the next eight years." Novato Unified lost 300 students over the prior two years, according to finance director Joshua Braff.

Mill Valley voters approved Measure E, a parcel tax, with 75% support in June. In a welcome letter to families, Kaufman cited the measure's passage as evidence of community engagement.

Families who enrolled for TK by Jan. 30 received placement letters on May 1, according to the district's enrollment page. The district said it would continue accepting applications and that all eligible students would be placed.