For researchers

The Atlas is the most complete public picture of Montessori in the United States, and every fact in it is traceable. If you study the field, report on it, or train the people who work in it, this page describes what you are looking at.

Sources. Listings are seeded from public data: the NCES Common Core of Data for public schools, the NCES Private School Universe Survey for private schools, and state licensing and nonprofit registry data added source by source. Schools then claim and maintain their own listings. Member directories of AMS, AMI, and the NCMPS Census are never ingested.

Provenance. Every field on every listing carries its source, its date, and whether it was seeded from public data, school-claimed, or verified with documentation. Listings display one of three trust states, and the state is never inflated.

Limitations, stated plainly. Survey-seeded facts age (the current private school data is from the 2021-22 PSS collection). Program levels derived from grade spans miss infant and toddler programs. Coverage of very small schools depends on public submissions. Counts on the stats page are counts of listings, not certainties about the field.

Citing the Atlas. Cite as: The Montessori Atlas, a Montessori Makers Group project, with the date you accessed it and the page URL. For questions about the data or bulk access for research, write to atlas@montessorimakers.org.