Choosing a school

The single most important thing to know before you start visiting schools is also the most disorienting: the word “Montessori” is not legally protected. In the United States, a 1967 trademark ruling, American Montessori Society, Inc. v. Association Montessori Internationale (155 U.S.P.Q. 591), found that “Montessori” has generic, descriptive meaning and cannot be owned by any single organisation. Anyone can put the word on a sign. The UK and EU situation is less settled and more case-by-case. AMI holds a logo mark there, not the bare word, and dozens of unrelated “Montessori”-branded entities coexist, but the practical result is similar: the name on the door tells you almost nothing by itself. What matters is training, affiliation, and what is actually happening in the room.

Disclosure: the author chairs the board of a Swedish Montessori school. See the conflict-of-interest disclosure.

What training and affiliation actually mean

Two organisations account for most formal Montessori teacher training worldwide, and they are genuinely different in how they operate. Neither is simply “the real one” and the other a lesser copy.

AMI (Association Montessori Internationale), the organisation Montessori herself founded in 1929, runs a single global syllabus with four separate age-specific diplomas: Assistants to Infancy (0–3, around 650 training hours), Early Childhood (3–6, a minimum of 400 hours), Primary/Elementary (6–12, a minimum of 440 hours), and Adolescent (12–18, around 740 hours). Training can be completed in one full academic year or spread across modular summer sessions, but always includes in-person, supervised teaching practice. This is the closest you can get to training as Montessori herself designed it.
AMS (American Montessori Society), founded in the US in 1960, takes a more flexible approach: typically one to two years, often blending in-person and online coursework with a practicum, and ongoing continuing education (50 hours every five years) to stay active. Rather than one centralised curriculum, AMS accredits a network of independently run Teacher Education Programs, which means more structural variety from one AMS-trained teacher to the next than you’d find across AMI.
MACTE (Montessori Accreditation Council for Teacher Education), founded in 1995 and based in the US, is the recognised accrediting body for Montessori teacher-training programmes, including, usefully, programmes affiliated with AMI, AMS, and other Montessori organisations, not just one. A MACTE-accredited credential is a reasonable baseline quality signal that doesn’t require you to have a view on AMI versus AMS.

In Sweden specifically, there is also Svenska Montessoriförbundet, the country’s own umbrella body and the administrator of its national teacher-authorisation exam, NAMEX. It is worth asking about, though it is a separate, Sweden-specific layer, not a substitute for AMI or AMS training. Since 2024, IMT (Institute of Montessori Training), a US-based provider unrelated to AMI despite the similar-sounding name, has also offered a Swedish-language 3–6 programme with a residency in Malmö; its diploma is MACTE-accredited but follows a different training lineage, via Elizabeth Caspari, than AMI’s. See the Glossary for more on each.

None of this means an unaffiliated, self-described “Montessori-inspired” school is automatically worse. Some are excellent; some use the name loosely on top of a fairly conventional classroom. It means the label alone cannot tell you which, so the next section matters more than any logo on the website.

What to actually look for on a visit

Ask to observe a working classroom, not just a staged tour, and watch for:

Mixed ages in one room: typically a three-year span (3–6, 6–9 or 6–12, and so on), not a single-year grouping.
Children choosing their own work from a visible, accessible range of materials, rather than all doing the same worksheet at the same time.
A long, uninterrupted block of work time, often cited as roughly three hours, where children are not moved between activities by a bell or a fixed timetable.
Calm, purposeful activity, not silence enforced from the front of the room and not chaos either. Genuine concentration tends to look busy but quiet.
Adults who mostly observe and occasionally guide one child or a small group, rather than lecturing the whole class from the front for most of the day.
Real materials in use, showing wear from actual handling, not beautiful but untouched shelving kept for photographs.
Grace and courtesy taught directly: how children are shown to resolve small conflicts, interrupt politely, or offer help, rather than left to adult intervention every time.
For older children: evidence of “going out”, research trips or projects that leave the classroom to answer a real question.

Questions worth asking directly

Which organisation trained the lead teacher, and is the credential MACTE-accredited?
What is the actual age range and group size in this specific classroom?
How long is the longest uninterrupted work period in a typical day?
How is a child’s progress tracked: through observation and portfolio work, through testing, or both?
What is the policy on worksheets, homework, and screens, especially below age six?
If the school describes itself as “Montessori-inspired” rather than AMI- or AMS-affiliated, what specifically does that mean here?
Who is the legal operator, and what structure is it (public body, company, foundation, non-profit association, or parent cooperative)?

A few honest cautions

Fidelity to the method varies enormously by country and by funding model. Publicly funded Montessori settings, in particular, sometimes blend Montessori materials into a more conventional, test-driven structure, and the research evidence for benefit is weaker at this end of the spectrum (see Understanding the Stages). A beautiful set of materials sitting unused is a worse sign than a slightly worn classroom in constant, purposeful use. And no credential, however reputable, substitutes for watching an actual classroom with your own eyes.

Legal structure is a separate question from funding. An independent school can be run as a company, a non-profit foundation, a religious trust, or a parent cooperative, where the families themselves are the legal members and often expected to contribute working hours. None of these structures by itself predicts fidelity to the method; ask directly who the legal operator actually is.

Where this leads next

Once you’ve found an environment you trust, Montessori at Home covers how to extend the same principles outside school hours, and FAQ and Myth-Busting addresses the questions and misconceptions that come up most often once a child is enrolled.

Sources consulted: American Montessori Society, Inc. v. Association Montessori Internationale, 155 U.S.P.Q. 591 (Trademark Trial and Appeal Board, 1967); AMI course documentation (montessori-ami.org); AMS Teacher Education Program documentation (amshq.org); MACTE, “History and Mission” (macte.org, 2024); montessoriforbundet.se/om-oss and sv.wikipedia.org/wiki/Svenska_Montessoriförbundet, for Svenska Montessoriförbundet; learn.aimmontessori.org/sweden-imt, for IMT.