AMI and AMS are two organizations that train and credential Montessori teachers, and both appear in what our research verified about the field — AMI diploma courses at training centres worldwide, and AMS-affiliated teacher education programs.
Which should you choose?
The differences that matter for getting hired are practical: whether a bachelor's degree is required, how long training runs, what it costs, and how the credential is named on the job posting you want.
AMI vs AMS: an overview
AMI and AMS train and credential Montessori teachers through different structures.
AMI works through training centres worldwide that offer diploma courses by age level — Assistants to Infancy (0-3), Primary (3-6) and Elementary (6-12) — plus a Montessori Classroom Assistant course.
AMS works through affiliated teacher education programs, and it ties its full credential to a bachelor's degree; graduates who have completed high school but do not hold a bachelor's can earn an AMS Associate credential at the Infant & Toddler and Early Childhood levels.
The training itself is described differently on each side.
AMI/USA describes AMI training as covering educational theory, child developmental psychology, classroom observation, practice teaching and material preparation, taught by AMI-certified trainers — and says the AMI diploma is recognized worldwide.
AMS describes its credential as typically 1-2 years of in-person or blended coursework, including discussions and hands-on activities, plus a yearlong mentored practicum.
One difference shows up directly in hiring: the names.
Each organization labels its levels its own way — AMI calls its 3-6 level Primary (also Casa dei Bambini or Children's House), while AMS names levels such as Infant & Toddler and Early Childhood — so check each organization's own age ranges rather than assuming the labels line up.
Before you pick, read postings for the jobs you want: they show which vocabulary the schools you are targeting use.
| AMI | AMS | |
|---|---|---|
| Training runs through | AMI training centres worldwide | AMS-affiliated teacher education programs |
| Age levels named | Assistants to Infancy 0-3, Primary 3-6, Elementary 6-12 | Infant & Toddler and Early Childhood (named in AMS credential rules) |
| Without a bachelor's degree | Not verified in our research — ask the training centre | AMS Associate credential at the Infant & Toddler and Early Childhood levels |
| Typical length | No fixed length verified; one centre's in-person 3-6 course runs nine months | Typically 1-2 years, including a yearlong practicum |
| Tuition | No AMI-wide price found in our research — cost examples below | Set by each affiliated program |
For the wider credential picture — levels by age band, how to choose, and what training costs — the Montessori teacher certification guide covers it in detail.
Format and length
On the AMS side, the organization describes the credential as typically taking 1-2 years, with in-person or blended coursework that includes discussions and hands-on activities, plus a yearlong practicum.
The practicum is mentored, and AMS says it can be completed at your current Montessori school if you already work in one — which matters if you are training while employed.
Each AMS-affiliated program sets its own schedule.
On the AMI side, diploma courses are organized by age level, and AMI/USA describes the training as educational theory and child developmental psychology, classroom observation, practice teaching and material preparation, taught by AMI-certified trainers.
For one concrete calendar: the Montessori Center of Minnesota's in-person AMI 3-6 Diploma Course runs nine months (2026-27).
That is a single training centre's published format, not a length our research verified across AMI courses.
The shape difference worth noting for interviews: the AMS route names a yearlong mentored practicum explicitly, while AMI training includes classroom observation and practice teaching among its components.
Either way, expect to talk concretely about your supervised classroom time — what you observed, what you practiced and how you were supervised.
About those specific hour counts
Recognition by employers
The honest starting point: our research found no employer-survey data ranking AMI against AMS among hiring schools, so this page will not guess at a preference.
What can be verified is how each credential is structured and what a school can check.
Three verified anchors: AMI/USA describes the AMI diploma as recognized worldwide.
AMS credentials come through AMS-affiliated teacher education programs, with a bachelor's degree behind every full credential.
And MACTE — the Montessori Accreditation Council for Teacher Education — has been recognized by the U.S. Secretary of Education since 1995 and accredits Montessori teacher education programs from Infant & Toddler through Secondary II and Administrator levels.
A school that wants to check your training can look up your program's MACTE accreditation status.
In practice, the match that matters is vocabulary.
Read postings for the jobs you want and note the credential and age level each names — and remember the two organizations name their levels differently: AMI's 3-6 level is Primary (Casa dei Bambini or Children's House), while AMS names levels such as Infant & Toddler and Early Childhood.
Check each organization's age ranges for the level you want, and put the exact credential, age level and training program on your resume so the match is visible to a skimming director.
Degree expectations can decide which postings you can answer.
Where a school asks for a full AMS credential, that requires a bachelor's degree; without one, high-school graduates can earn an AMS Associate credential at the Infant & Toddler and Early Childhood levels.
For AMI, our research did not verify a degree requirement either way, so ask both the training centre and the schools you are targeting.
A Montessori credential is not a state license
What AMI and AMS training cost
AMS says each of its affiliated programs sets its own schedule and tuition, so the AMS cost question is answered program by program.
For AMI, our research found no AMI-wide price — only two published examples from U.S. training centres, presented as examples, not an average.
We did not confirm an average Montessori tuition, and you should expect to price individual courses yourself.
| Published example (AMI 3-6 / Primary) | Montessori Center of Minnesota | Montessori Northwest |
|---|---|---|
| Tuition | $14,500 total, nine-month format (2026-27) | $14,500-$14,750 depending on format |
| Application fee | $75 | $150 |
| Books | Not listed in our research | About $250-$300 |
| Supplies | Not listed in our research | $300-$600 |
| Membership | Not listed in our research | $99 AMI membership |
Before you budget the full amount, check the aid that exists.
AMI/USA runs a fund that awards partial scholarships — tuition reductions — toward AMI training in the United States, and it lists Montessori schools offering to sponsor trainees.
If you already work at a Montessori school, sponsorship is a conversation worth having with your director before you enroll.
Whichever route you price, ask the program what tuition does and does not include — our research found different extras listed for the two examples above, so check each course's own fee sheet before you budget.
Other MACTE-accredited options
The AMI-versus-AMS question is not the whole map.
MACTE — which has been recognized by the U.S. Secretary of Education since 1995 — accredits Montessori teacher education programs from Infant & Toddler through Secondary II and Administrator levels.
Whatever affiliation a program claims, its MACTE accreditation status is a check worth making before you pay.
Two details make that check reliable.
MACTE accredits the teacher education program itself, not the college or school that houses it — so a familiar institution name is not the credential; the program's own status is.
And our research found no published total of MACTE-accredited programs: the directory is a dynamic search, so searching it for programs at your level and in your format is the practical step.
If you need a mostly-online format, note one rule MACTE sets: accredited programs that deliver more than 50% of their academic content online must still require at least 120 residential (in-person) hours, and MACTE's directory filters programs by online share.
The online Montessori teacher training guide walks through that question in detail.
Whichever route you choose, the hiring move is the same: name the credential, the age level, the training program and its accreditation or affiliation on your resume, and match it to the postings you want.
Then confirm the state layer with the licensing agency where you want to work.
This page is career information, not licensing or legal advice. Confirm training and credential questions with the program and its accrediting body, and state staff requirements with your state child care licensing agency.