Cornerstone Montessori

Sumner, Washington 98390

See this school on Google Maps →
Call (253) 987-7239

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

Programs, tuition & schedule

Quoted from cornerstonemontessori.online.
"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."
— Cornerstone Montessori, homepage ↗

Accreditation & affiliations

  • AMS · member
  • MACTE · member

Source: school's homepage ↗

Programs offered

  • Toddlers
  • Primary Part Time
  • Full Time Primary
  • Elementary

Source: school's Toddlers page ↗

Schedule

View the school calendar ↗

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.

How to apply

Quoted from cornerstonemontessori.online.
  1. Fill out an application
  2. Pay app fee ($50 per student)
  3. Connect via tours or phone calls
  4. Wait for an opening
  5. Student visit (mid-year or elementary enrollment)
  6. Seat offered once enrollment approved

Source: school's Process page ↗

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.

Call Directions