Montessori schools in U.S.
Because there is no single registry or even uniform definition of what constitutes a Montessori school, there is some dispute as to the number of private Montessori schools in the United States. Estimates range from just under 4,000 to greater than 8,000. There are about 250 public and 120 charter schools that include Montessori programs (see below). Most private schools have a primary program (from 3–6 years) and often a lower elementary (6–9 years). Upper elementary programs (9–12 years) are less common, although about one school in eight will have this program. At this time Montessori junior highs and high schools are rare. However, the first public Montessori high school in the country, Clark Montessori located in Cincinnati, Ohio, was started in 1994. Several pilot Montessori junior high schools have opened based on writings by Montessori on Erdkinder, German for "children of the land", which was a term Montessori coined for children ages 12 through 18. The last few years have seen the advent of infant and toddler Montessori programs. Many schools offer "mother and child" programs in which parents can learn about Montessori and how to apply the philosophy to their child-rearing practices. In many other schools, the demand for high-quality childcare has spurred the growth of Montessori infant, or "nido" (the Italian word for "nest") and toddler, or "infant community" programs.
The Montessori community has no central authority. Although the American Montessori Society (AMS), located in New York City, is by far the largest Montessori organization in the United States, it affiliates only about 25 percent of the schools that call themselves “Montessori.” Many other schools across the country are affiliated with other Montessori organizations or with no organization at all.
Accreditation and quality standards for Montessori teacher education are provided through the Montessori Accreditation Council for Teacher Education Commission located in Racine, Wisconsin. MACTE is the only entity in the United States licensed to accredit teacher programs for Montessori across all philosophical styles by the US Department of Education. Non-MACTE accredited programs cannot be considered diploma programs or trade schools, and holders of certifications from those training centers are not eligible to teach in most Montessori schools (other than those accredited by the training centers themselves). For Montessori schools, various organizations provide quality standards through affiliation, recognition, or membership according to their own particular philosophy, procedures and requirements.
1. 2008 Montessori Community Resource, p.16, Jola Publications.