AMI vs AMS Montessori School: 5 Differences & Similarities

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AMI vs AMS Montessori

Montessori schools are educational institutions that adhere to the methodology and approach developed by Dr. Maria Montessori. 

These schools have a global presence and have significantly influenced the field of education. 

Dr. Maria Montessori, the founder of the Montessori education system, played a pivotal role in popularizing and spreading this approach, particularly in the United States.

Accreditation for Montessori schools is provided by two organizations: the American Montessori Society (AMS) created by Nancy Rambusch and the Association Montessori Internationale (AMI) created by Dr. Maria Montessori and her son, Mario.

AMS Montessori and AMI are two organisations that provide training and accreditation for the Montessori system.

Established in 1960, Rambusch created AMS as a subsidiary of the larger international AMI organization. 

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    However, differences in teaching approaches between AMI vs AMS Montessori led to growing tensions. In 1967, the U.S. Patent Office ruled that the term “Montessori” referred to a specific educational method and was not exclusive to AMI’s academies. 

    This ruling created a formal separation between the two branches, resulting in competition for official recognition in the United States over the following two decades. 

    Despite this, since the 1990s, the two organizations have reconciled and occasionally collaborate to promote Montessori education globally. 

    A notable recent joint effort is the Montessori Public Policy Initiative, which advocates for the implementation of high-quality Montessori education.

    These organizations ensure that Montessori schools meet certain standards and uphold the principles of Montessori education.

    However, if you are still jumpstarting your journey to Montessori education, you may ask, what are the differences and similarities between the two?

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    In this article, we discuss how AMI and AMS training differs from each other as well as the similarities of Montessori education to aid you in deciding which is better for your needs and goals!

    What is the Association Montessori Internationale or AMI?

    Maria Montessori and her son Mario set up AMI in 1929. The AMI Montessori is headquartered in Amsterdam.

    AMI (Association Montessori Internationale) was founded by Maria Montessori and her son, Mario, in 1929 and has its main headquarters in Amsterdam, Netherlands. 

    AMI trained schools to follow the Montessori approach and curriculum in a manner that closely aligns with Maria Montessori’s original approach. 

    These schools adhere strictly to the use of Montessori materials as intended by Dr. Montessori, without any modifications or additions, with the aim of maintaining the method’s purity according to the proponents of this interpretation.

    If you prioritize an authentic Montessori training program for your child without external influences or dilution of the method, it is advisable to seek out schools that align themselves more closely with AMI.

    What is the American Montessori Society or AMS?

    AMS refers to a Montessori created by Nancy McCormick Rambusch, a teacher trained in the AMI method in the late 1960s. This served as her brainchild to propagate Montessori learning but with deviations from the original true Montessori pedagogy.

    Rambusch believed that certain aspects of the Montessori method needed to be modified to better suit the cultural context of the United States.

    In AMS schools, teachers adhere to the fundamental principles developed by Dr. Montessori while incorporating external resources, materials, and ideas to enhance the Montessori curriculum. 

    This may include the integration of technology and the incorporation of current events.

    For parents who value computer skills and a broader understanding of current events, it is recommended to seek out schools that align more with the AMS approach. 

    These schools are likely to provide opportunities for students to learn computer skills such as creating reports using Word and presentations using PowerPoint when they are developmentally ready, as well as knowledge about relevant current events.

    Difference Between AMS and AMI Montessori

    1. Curriculum

    AMI schools strictly adhere to the curriculum and methodology originally conceived by Maria Montessori, ensuring the preservation of the method’s purity. 

    On the other hand, AMS deviate from the original Montessori methodology by allowing teachers to incorporate external materials, ideas, and resources into their classrooms.

    1. Teacher training

    AMI Montessori follows a standardized teacher training method, ensuring consistency across different training centers. 

    This standardization also extends to the teaching approach used in AMI Montessori classrooms, providing a uniform learning experience from the early stages to the higher levels. 

    Consequently, if a child transitions from one AMI Montessori school to another, they can expect a seamless continuation of their education. 

    In contrast, AMS schools do not have the same level of teaching uniformity. 

    As a result, if a child changes schools, they may not experience the same continuity in their education.

    1. Mission and Vision

    AMI’s mission is to facilitate the organic growth of individuals from infancy to adulthood, empowering children to become catalysts for positive change in society and contributing to a balanced and peaceful global community. 

    Its vision is to be acknowledged globally as a respected authority on the distinctive characteristics of childhood, the innate progression of human development, and the rights of children. 

    It is widely recognized and esteemed both nationally and internationally as the guardian and promoter of Montessori principles and teaching methods.

    On the other hand, AMS aims to offer guidance and support in order to establish Montessori as a prominent and lasting presence in the field of education. 

    It is dedicated to serving members, advocating for the delivery of high-quality Montessori education, and championing the fundamental principles of Montessori.

    Lastly, they envision creating a world where the value of quality Montessori education is universally acknowledged, eagerly sought after and made accessible to everyone.

    1. Compatibility

    AMS schools are customized to suit the specific location and exhibit a distinctiveness that is specific to each individual school. 

    On the contrary, AMI schools adhere to a standardized approach to teaching, which limits the uniqueness of each school’s teaching style.

    1. Facilities and affiliated schools

    Training centers employ trainers who specialize in a particular Montessori model and are obliged to undergo thorough preparation. 

    AMI follows more standardized procedures across its centers, whereas AMS allows for greater flexibility in terms of how training is delivered, its cost, and its format. 

    While the AMI headquarters is situated in Amsterdam, the organization has a global presence with offices, projects, approved resources, and affiliated societies around the world. 

    It operates 68 affiliated training centers worldwide and maintains a significant presence in the United States. 

    On the other hand, AMS originated in the United States and has its headquarters in New York. 

    It has surpassed AMI as the largest Montessori organization globally, boasting over 1,300 member schools, more than 13,000 individual members, and nearly 100 AMS–affiliated teacher education programs. 

    In general, AMS has established a stronger foothold in the region compared to AMI.

    AMS vs AMI Montessori Training: How Are They Similar?

    The learning environment in both AMI or AMS classes shares many similarities in terms of physical space and materials. 

    Both models advocate for a 1:15 adult-to-student ratio. 

    The classrooms in both systems are designed to be visually appealing, welcoming, spacious, and easily accessible to students, allowing them to independently access materials and take charge of their learning. 

    Creating distinct areas for various activities, such as group work or individual quiet time, is also emphasized in both AMI or AMS.

    Furthermore, both types of classrooms are equipped with approved materials that are specifically designed to focus on teaching a single skill or concept at a time. 

    Educator training in both models encompasses both class instruction and practical components. 

    Typically, this involves around 300 to 400 hours of class work and a year-long practicum. 

    The training covers a range of aspects, including knowledge, pedagogy, and teaching style within the Montessori approach.

    While AMI formally qualifies Montessori Assistants, AMS does not have a similar qualification process. Additionally, both AMI and AMS Montessori emphasize the importance of ongoing professional development for educators. However, AMS requires a minimum of 50 hours of professional development every five years, while AMI does not have a specific requirement in this regard.


    In conclusion, experts generally recognize the legitimacy of both AMI and AMS models, and no research has been found that directly compares the outcomes between the two. 

    AMI is widely regarded as the orthodox Montessori model, characterized by a steadfast adherence to its philosophy and pedagogy. 

    In contrast, AMS is more inclined to adapt and incorporate new educational paradigms, making it a more flexible and dynamic system. 

    Despite their divergent approaches in the syllabus, and training, both organizations are actively promoting the credibility of Montessori education in the United States as an alternative to conventional educational models.


    What is AMI certification? AMI certification is a professional certification for Montessori teachers that is recognized worldwide. It is awarded by the Association Montessori Internationale (AMI), an international organization that promotes Montessori education. To become an AMI-certified teacher, candidates must complete a rigorous training program that includes coursework in Montessori philosophy, child development, and Montessori teaching methods. They must also complete a practicum in a Montessori class.

    Is AMI certification better than AMS? The question of whether AMI certification is better than AMS is subjective and depends on individual perspectives and needs. Both AMI and AMS have their own merits and considerations. AMI is often seen as adhering closely to the original Montessori philosophy and methodology. On the other hand, AMS certification is offered by the American Montessori Society, which has evolved over time and incorporated some adaptations to the Montessori method to suit the American culture and educational context.

    How do you get Montessori certified? There are many ways to become Montessori certified. Some of the most common ways include taking a Montessori teacher training program, getting a Montessori teaching degree, or getting certified through Montessori organizations other than AMI such as MACTE or the Montessori Accreditation Council for Teacher Education.