Evaluating Montessori Preschools: Cost-Effective Developmental Gains

A randomized national trial of public Montessori preschools—randomizing nearly 600 children across roughly two dozen programs—found stronger early reading, memory, and executive function at kindergarten entry, with benefits visible across socioeconomic groups; a separate cost analysis reported substantially lower operating costs per child.

The lottery-based evaluation compared Montessori enrollment with standard preschool options and assessed outcomes at kindergarten entry, providing a rigorous population-level test of Montessori in public settings. Montessori attendees showed improvements in reading, memory, and executive function; these effects were consistent across sociodemographic strata and align with common kindergarten-readiness benchmarks.

A cost analysis estimated about $13,000 lower operating cost per child across ages 3–6 in public Montessori programs. Savings derived mainly from mixed-age classrooms, durable and reusable learning materials that reduce per-child supply turnover, and staffing structures that emphasize multi-age supervision rather than duplicative staffing. Those efficiencies did not appear to reduce measured learning outcomes in reading, memory, or executive function.

Gains in reading and executive function plausibly translate into downstream academic benefits: these domains predict smoother transitions to formal instruction and better trajectories in early grades. The trial’s pattern of sustained advantages suggests continued learning benefits consistent with improved long-term outcomes, but longitudinal follow-up is needed to confirm persistence beyond early elementary grades—so the longer-term effects remain promising but not yet definitive.

The public Montessori model also offers scalable implementation levers—structured mixed-age grouping, focused teacher preparation in Montessori pedagogy, centralized materials procurement, and routine fidelity monitoring—that districts can deploy without proportionate cost increases. Budgetary savings could be reallocated to training and oversight; practical capacity needs center on workforce development and fidelity checks to preserve program integrity.

Adoption at scale therefore appears feasible with targeted investments in training and implementation supports.

Key Takeaways:

• A randomized national trial found stronger reading, memory, and executive function by kindergarten in public Montessori preschools, accompanied by notable cost efficiencies—findings worth piloting in districts.
• Children enrolled in public Montessori preschools across socioeconomic groups—showing improved early-development indicators tied to school readiness.
• Early childhood programs and education administrators may pilot scaled Montessori implementations while tracking fidelity and outcomes to validate broader impacts.