Is It Real Montessori? AMS vs AMI vs “Montessori-Inspired”

Here's the fact that changes everything about your search: “Montessori” is not a protected word. Any school can put it on the door, whether or not it follows the method or employs a single trained guide. Telling authentic from branding is the parent's job — this is how to do it.

“Montessori” is not a trademark

In 1967 a US trademark ruling found that “Montessori” has a generic, descriptive meaning and cannot be owned by any organization. The name is effectively in the public domain. There is no legal standard a school must meet to use it — so a rigorous, credentialed program and a daycare that bought some wooden toys can carry the same label. That's not a scandal; it just means the responsibility to verify sits with you.

AMI vs AMS — the two main bodies

Two organizations set the widely-recognized standards and train teachers:

AMI (Association Montessori Internationale) — founded in 1929 by Maria Montessori and her son, headquartered in Amsterdam. It's the more traditional lineage, and the only body Montessori herself established.
AMS (American Montessori Society) — founded in 1960, the largest Montessori organization in the US, generally seen as somewhat more flexible and adapted to American schooling.

Both train teachers and accredit schools. Neither is “the real one” — a strong school can be AMI or AMS. In New York City, many independent schools are also accredited by NYSAIS (the state association of independent schools), which is a separate, rigorous accreditation.

Accreditation vs. membership — a crucial difference

This trips up a lot of families. A school can be a member of AMS or AMI simply by joining; accreditation is a much higher bar that involves a formal review of the school's program, teachers and fidelity to the method. Most member schools are not accredited. So “AMS member” and “AMS-accredited” are very different claims — and marketing often blurs them.

Teacher credentials & MACTE

An authentic Montessori guide holds a credential for the specific age level they teach (Infant/Toddler, Primary 3–6, Elementary 6–12, or Secondary). Training programs are accredited by MACTE, a body recognized by the US Department of Education. A generic early-childhood degree, on its own, is not Montessori training.

How to vet a school in five checks

Credentialed guides. Every lead teacher holds an AMS, AMI or MACTE-accredited credential for that age level.
A full work cycle. A protected ~3-hour uninterrupted morning block (about 2 for toddlers) — not 45-minute periods.
Genuine mixed ages. True three-year age spans (3–6, 6–9), not single-grade rooms relabeled “Montessori.”
Complete, authentic materials. Full, sequenced Montessori materials across practical life, sensorial, language, math and culture.
Few worksheets or screens. Heavy reliance on worksheets or screens — especially under age six — is the clearest sign of “Montessori-inspired” rather than the real thing.

You can confirm membership and accreditation directly in the AMS and AMI school directories, and simply ask a school which credentials its guides hold and how long the work cycle is. An authentic school welcomes the question.

How this guide labels it

Because this distinction matters so much, every school in our directory carries an authenticity label — AMS-accredited, AMI-recognized, AMS/AMI member, IB, or “Montessori-inspired” — alongside a staff-transparency rating for how openly the school discloses who teaches and their credentials. Those two signals, together, are the fastest way to separate substance from branding.

Browse schools by authenticity and transparency on the directory, then use the choosing guide to plan your tours.

Sources: American Montessori Society (amshq.org); Association Montessori Internationale (montessori-ami.org); MACTE (macte.org); 1967 US Trademark Trial and Appeal Board ruling on the “Montessori” mark. Practical guidance, not legal advice. Last reviewed July 2026.