John Wister Elementary | Mastery Charter School

Your Neighborhood School in East Germantown

Welcome to Wister Elementary! We’re a neighborhood elementary school serving over 500 students and their families in Kindergarten through 5th grade.

Wister offers children academic excellence in a fun, joyful environment. From math to music and reading to field trips, our students receive a well-rounded education from loving teachers and leaders.

We focus on 5 core values: respect, responsibility, hard work, teamwork and kindness.

Wister students have the opportunity to automatically attend our Pickett Campus for 6th – 12th grade, giving them a full K-12 Mastery experience.

At Wister, we believe all of our students have greatness within. With love and high expectations, we support them in finding their own paths to success.

Stop by and visit us any time!







Our School

  • Students come to school excited to start their day, with their laptop in hand.  
  • The day starts with free breakfast.
  • Students are greeted by their teacher and head to their classroom for morning meeting.  
  • We value reading.  Students have at least 2-3 hours of reading where they work in small groups with the teacher.  
  • Students have classes in math, social studies, and science.
  • Students head back to the cafeteria to enjoy free lunch.
  • Afterwards, students enjoy free play or structured recess.
  • Students engage in art, physical education, music or Spanish. We are proud to educate the whole child at Mastery.
  • Once the school day is over, students may stay to participate in clubs or the aftercare program.  

Learn more about our K-12 Approach.

Wister offers a variety of after school activities and clubs.  Aftercare is available through local providers.

Some examples include:

  • Art Club
  • Basketball
  • Book Club
  • Cheerleading
  • Choir
  • Cooking Club
  • Games Club
  • Homework/Tutoring Club
  • Lego Club
  • Performing Arts
  • Reading Enrichment
  • Running Club
  • Step Club

John Wister Elementary serves students in the East Germantown community who live in the school’s attendance zone within the 19144 zip code.

The school cannot enroll students living outside of its attendance zone, even if they reside within the listed 19144 zip code.

Our Team

Ashley Langston, Principal

[email protected]

Ashley Langston has been the principal at Mastery Charter School Wister Elementary since 2019. She started her education career as a teacher at Mastery’s Cleveland Elementary and also served as an apprentice school leader, assistant principal of instruction and assistant director in the central office where she supported and coached assistant principals of instruction across the Mastery network. Mrs. Langston brings deep content knowledge, excellent relationship building skills and a fierce commitment to delivering world-class instruction to our students


A native of Baltimore, Maryland, she transitioned to Philadelphia In 2006 to attend Temple University where she earned a B.S in Early Childhood/Elementary Education. In 2011, she attended Philadelphia College of Osteopathic Medicine (PCOM) where she earned an M.S in Organizational Development and Leadership (ODL). In 2019, she completed the Pathways to Leadership in Urban Schools where she earned her principal certification.


As a child, she fell in love with poetry and performed spoken word poetry in her adolescent years.


Kellie Gilroy, Assistant Principal of Operations

[email protected]