Sumner, Washington 98390 On Google Maps →
Cornerstone Montessori
- NS-6
- Grades
- Primary · Elementary
- Levels
- 26.6 : 1
- Ratio
- 133 students
- Enrollment
Facts & figures
From government filings and independent surveys — not the school's own marketing.
- Student-teacher ratio
26.6 : 1
133 students · 5 full-time-equivalent teachers
U.S. Dept. of Education private school survey, 2021–22
- School day
6 hours/day · 190 days/year
U.S. Dept. of Education private school survey, 2021–22
- State license
Licensed child care center
Capacity 132 · licensed since 2003
Washington State DCYF, 2026
From the school
Programs, tuition & schedule
"Cornerstone Montessori remains committed to partnering with parents to grow courteous and courageous explorers of the world. We do this by creating safe, prepared environments where students have opportunity to learn, fail then try again, explore and practice values of respect, independence, and self-regulation."
Programs offered
- Toddlers
- Primary Part Time
- Full Time Primary
- Elementary
Source: school's Toddlers page ↗
Schedule
Some fields above are blank because they weren't published on the school's site. Call or email the school for tuition, admissions, and other details not listed here.
Admissions
How to apply
- Fill out an application
- Pay app fee ($50 per student)
- Connect via tours or phone calls
- Wait for an opening
- Student visit (mid-year or elementary enrollment)
- Seat offered once enrollment approved
Source: school's Process page ↗
Good to know
About Cornerstone Montessori
Cornerstone Montessori is a Montessori school in Sumner, Washington serving grades NS-6. Cornerstone Montessori remains committed to partnering with parents to grow courteous and courageous explorers of the world. We do this by creating safe, prepared environments where students have opportunity to learn, fail then try again, explore and practice values of respect, independence, and self-regulation.
Where is Cornerstone Montessori located? ⌃
1644 Gault St, Sumner, WA 98390
What is the phone number for Cornerstone Montessori? ⌃
Cornerstone Montessori can be reached at (253) 987-7239.
Is Cornerstone Montessori accredited? ⌃
Cornerstone Montessori lists the following accreditations or affiliations on its website: AMS (member), MACTE (member).
How do you apply to Cornerstone Montessori? ⌃
Cornerstone Montessori's admissions process: Fill out an application; Pay app fee ($50 per student); Connect via tours or phone calls; Wait for an opening; Student visit (mid-year or elementary enrollment); Seat offered once enrollment approved.
What ages does Cornerstone Montessori serve? ⌃
Cornerstone Montessori serves grades NS-6.
What is the website for Cornerstone Montessori? ⌃
The official website is cornerstonemontessori.online.