Standards for AMI Montessori Classrooms

AMI pedagogical standards maintain the level of excellence that Maria Montessori envisioned. Established by the AMI Scientific Pedagogy Group, the standards insure that each school offers programs for their children that allow for their full intellectual, social, and psychological growth and that the approach is consistent with what is presented in AMI training courses worldwide.

The Teacher

There will be one AMI trained teacher at the appropriate age level in each class.


Each class may have one non-teaching assistant. Should local regulations make it necessary to have more than one aide, he/she should be a non-teaching aide and should assist the directress by making materials, supervising outdoor activities, and assisting with field trips or “going-out.”

The Materials

Each classroom must be equipped with a complete set of Montessori materials from an AMI approved manufacturer. These materials are available through one of the following AMI recognized distributors in the United States: The Juliana Group, Inc. (Gonzagarredi) or Nienhuis Montessori USA.

The Classes

Number of Children

Classes include a well-balanced division of ages as well as an appropriate number of children to ensure social development:

Nido:  6-9 children

Toddler: 10-14 children

Primary: 24-35 children

Elementary: 24-35 children

Age Range

Classes are made up of children in the following age ranges (ages listed are approximate):

Nido (infant environment): 2 months to 12/15 months

Toddler Community: 12/15 months (walking well) to 3 years

Primary class: 3-6 years

Elementary class: 6-9 & 9-12 years, or 6-12 year

Uninterrupted Work Period

Classes are scheduled five days per week (unless specified otherwise) with substantial uninterrupted work periods every day:

Toddler: 2 hours per day, at least four days a week

Primary: 3 hours per day every morning for all children, and 2-3 hours per day every afternoon for the older children (extended day)

Elementary: 3 hours per day every morning, and 2-3 hours four afternoons per week


A consultation by an AMI trained consultant is required at least once every three years.

AMI School Recognition Status

The AMI school recognition program was initiated in the United States to assist parents in assessing whether schools are following Montessori’s principles and practices in their original integrity and completeness. It is upon these standards that AMI recognition is granted.

A school applies to become an AMI-Montessori school annually. The recognition status is based upon the training of their teachers as well as their compliance with the pedagogical standards. There are three different status levels offered:

AMI Recognized

To receive an AMI Certificate of Recognition a school must be in compliance with all of the AMI standards, the most significant of which is that there is an AMI trained head teacher at the appropriate age level in each classroom.

For schools that do not meet all of the standards, AMI/USA offers two alternatives:

AMI/USA Affiliated

To qualify for Affiliated Status, 80% of the head teachers must hold the appropriate AMI diploma and the school must meet all other AMI standards.

AMI/USA Associated/Public Schools

To qualify for the Associated status, 50% of the head teachers must hold an AMI diploma, and at least one must be teaching at the appropriate age level. The Associated status is also a transitional category for schools that are in the process of developing programs that meet all of the AMI standards.

Most public schools apply at this level due to the fee structure offered public schools, although many meet all requirements for AMI recognition.

Grace Period

Affiliated and associated schools are granted this status based on the fact that they are aspiring to become AMI recognized schools. These schools are given a grace period of up to three years in which to meet the requirements for AMI recognition.

AMI Trained Teacher*
Non-teaching Assistants
1 per 5 or 6 children (toddler)
1 per 3 children (nido)
Consultation visit at least once every three years
Complete set of Montessori materials from an AMI approved manufacturer
Children of a mixed three-year age group, including a well-balanced division of ages
(ages listed are approximate)
Parent/Infant or Nido:
2 months to
12/15 months
12/15 months
to 3 years
3 to 6 years
6 to 9, 9 to 12,
or 6 to 12 years
Classes with an appropriate number of children to ensure social development
10-14 children (toddler)
6-9 children (nido)
24-35 children
24-35 children
work cycles (uninterrupted)
2 hours per day,
4 days per week
3 hours per day,
5 days per week
prolonged work periods,
5 days per week**
work cycles

Not required
2-3 hours per day,
5 days a week
prolonged work periods,
4 days per week**
* Some schools are temporarily unable to meet this requirement. If a school is unable to meet this requirement, they may apply for Affiliated or Associated status.
**Elementary Work Periods: At the elementary level, prolonged uninterrupted work periods are required every morning and afternoon, with an exception being one afternoon a week which may be left free to accommodate additional subjects. In practical terms, what this means is that for each elementary class, one afternoon each week may be set aside for special subject such as foreign language or physical education. Out of a possible ten work periods per week, nine must be reserved for Montessori work. Other special subjects can be scheduled in such a way that there is still an uninterrupted work period.