AMI or Association Montessori Internationale, is the international association for Montessori schools. Maria Montessori and her son set up the AMI in 1929 and the organization's headquarters are in Amsterdam. Nancy McCormick Rambusch was an AMI trained teacher who set up the AMS, or American Montessori Society, in New York in 1960. She felt that the original Montessori philosophy and curriculum needed to be adapted for American culture.
In the AMI system, all Montessori teachers go through the same program and receive the same training, regardless of which training center they attend. This ensures that all AMI-certified teachers approach Montessori education in the same way. Although AMS Montessori teachers also complete an education program to become certified AMS Montessori teachers, there is a bit more variation among different certification centers.
AMI Montessori schools adhere strictly to the curriculum and guidelines that Maria Montessori originally developed. The curriculum is standardized at all grade levels and between all schools. This means that if your child moves from one AMI Montessori school to another, the curriculum, activities and teaching methods will be identical. Because AMS Montessori school teachers have learned their craft at different training centers that have varied focuses, there is a bit more variation for AMS Montessori students from school to school.
AMI Montessori schools keep to Maria Montessori's original curriculum. In order for a school to be certified as an AMI Montessori school it must have a complete set of age-appropriate materials. In AMS Montessori schools the curriculum has often been adapted a bit from Maria Montessori's original standards. AMS Montessori schools allow teachers to bring in outside materials to supplement the Montessori materials. AMS schools also incorporate more current American ideas about education into the Montessori method.