Infant, Toddler or Preschool? Choosing a Montessori Program for a Child Under Six

Start with your child’s age, then weigh readiness and the hours you need. In AMI’s standards, babies from about 2 months join a Nido, children from about 12 or 15 months an Infant Community, and children from about 2.5 or 3 a class for ages 3 to 6. Because those ages overlap, the harder decision usually comes near age 3, when a child could stay in a small toddler group or move up to a much larger preschool class.

How Do the Three Programs Compare?

	Infant (Nido)	Toddler (Infant Community)	Preschool (Primary, 3 to 6)
Ages in AMI standards	2 months to 12 or 15 months	12 or 15 months to 2.5 or 3 years	2.5 or 3 to 6 years
Ages in AMS terms	Birth to 18 months	15 months to 3 years	2.5 to 6 years
Adults per child (AMI)	1 to 3	1 to 5 or 6	One AMI-trained teacher, plus one non-teaching assistant allowed
Group size (AMI)	Up to 9 or 10	10 to 14	24 to 35
Work period (AMI)	None required	2 hours every morning	3 hours every morning, 2 hours every afternoon
Day elements to ask about	Feeding, sleep, diapering, your baby’s main caregiver	Meals children help serve, naps, toilet learning, settling in	Length of the work period, lunch, rest, the kindergarten year

AMI figures come from the AMI/USA classroom standards and AMS ages from the AMS glossary, both read in November 2026. AMI calls its ages approximate.

What Should I Ask About a Montessori Infant Room?

AMS describes a Nido for babies who are not yet mobile or are crawling, with bars to pull up on, mirrors, a sleeping area with floor beds or mats, and small tables and chairs in place of high chairs (AMS, Infant and Toddler). AMI requires no set work period at this age, so the day follows each baby’s feeding and sleep rather than a timetable.

• Will my baby be fed on demand or on a schedule, and who prepares the bottles or food?
• Where does my baby sleep, and how does the room follow safe sleep rules?
• Which adult will be my baby’s main caregiver, and who covers their days off?
• How will you tell me about feeds, naps and diapers each day?

To compare two infant settings line by line, use the sheet in our guide to Montessori daycare.

What Should I Ask About a Toddler Group?

From about 12 or 15 months, children move into a group of 10 to 14 with a two-hour work period each morning. AMS describes toddlers helping prepare, serve and clean up their snacks and meals, a self-care area for washing and toileting, and floor beds that let children get into and out of bed on their own.

• How does settling in work during the first two weeks, and can I stay for part of it?
• Do children wear underwear, pull-ups or diapers here, and how do you handle accidents?
• What does a child who doesn’t nap do during rest time?
• Who will tell me if my child is still upset after drop-off?

Toilet learning often decides the timing of the next move, and our guide to potty training and Montessori preschool covers what schools ask for.

When Is a Toddler Ready for the 3 to 6 Class?

The move is bigger than it looks on paper. A child goes from a group of 10 to 14, with an adult for each five or six children, to a room of 24 to 35 children aged up to 6, with one teacher and one assistant, and from a two-hour morning to three hours of mostly independent work.

Schools judge readiness differently, often by speech, independence and toileting as well as age. Our guide on what age to start Montessori covers what one AMI trainer looks for, along with entry ages and cutoff dates. Visit both rooms if you can, since a confident 2.5-year-old and a cautious one can need different answers.

What Should I Ask About the Preschool Class?

By 3, most of the questions shift from care routines to the class itself and the years ahead.

• How many children are in each year of the three-year cycle right now?
• Is this a half-day or full-day place, and what happens in the afternoon?
• Where do younger children rest after lunch?
• What is the third year called here, and does tuition change that year?

Our guide to what a Montessori preschool is walks through the class in more detail, and the primary program page covers each year.

How Do Hours and Cost Differ Between the Rooms?

Ask for the fee of each room separately. Rooms with more adults per child often cost more, so the same school can charge very different prices for a 14-month-old and a 3-year-old. Check, too, whether the group’s day matches the hours on the door, because early and late care is often a separate charge. Our guides to Montessori school costs and Montessori for working parents help you add it all up.

To see what’s near you, open your city from find Montessori schools near you and use the Program filter for Infant, Toddler or Preschool. Our program tags come from public listings and miss many baby and toddler rooms, so a school tagged only Preschool may still take younger children. Check its own website or call.