From a K-4 charter on Tulip Street to a K-8 campus on Longshore Avenue — the story of two decades of growth.
Keystone Academy Charter School · 4521 Longshore Avenue, Philadelphia
Keystone Academy Charter School (KACS) in Philadelphia began in 2007 as Planet Abacus Charter School, a K-4 public charter school. It added a grade each year until it became a K-8 school. Its original five-year charter began July 1, 2007, and was renewed in 2012.
A New Era of Governance
2012–2014
That renewal came during a period of reorganization after problems involving former Planet Abacus administrators. In 2012, Dr. Claudia Lyles was appointed interim CEO, and in August 2013 she became CEO.
Dr. Claudia Lyles · Chief Executive Officer
Working with the Board of Trustees, she rebuilt the board, led the charter-renewal process, put stronger fiscal controls in place, clarified the roles of the board and the CEO, and improved board training. In April 2014 the school took the name Keystone Academy Charter School, and the School Reform Commission approved the change that June.
The new name marked the school’s independence and stronger governance.
The Move to Longshore Avenue
2016–2017
Those reforms made the school’s next step possible. In February 2016, the Keystone Foundation bought the property at 4521 Longshore Avenue, in the Tacony section of Philadelphia, for about $1.145 million. The site held the historic Mary Disston School, built around 1900. BSI Construction preserved parts of that building and added a new school building beside it.
The campus was designed to support Keystone’s focus on science, mathematics, technology, and the arts. It has science laboratories, dedicated spaces for art, computers, music, and physical education, and a large library. Less than five years after Dr. Lyles took over as CEO, the school had bought and built its permanent home. It replaced the former location at 6660 Keystone Street.
The 2016–17 Board of Trustees oversaw the project:
Gretchen Maldonado Alston
President
Fred Phelps III
Vice President
Marie McCarthy
Secretary
Alma M. Diggs
Treasurer
Lieutenant Tina Peterson
Member
Christina Godfrey
Member
Howard Randolph
Member
Students, families, elected officials, and community members joined Dr. Lyles and Mrs. Alston at the open house and ribbon-cutting on June 3, 2017.
Open House & Ribbon-Cutting · June 3, 2017
Recognition & Renewal
2018–2022
Recognition followed quickly. In 2018, the School District of Philadelphia named Keystone a Peer Leader based on its 2016–17 performance, and the mayor recognized it as a “Most Improved School.” In 2019, the school completed the “Idea Box,” its engineering space. In 2021, U.S. News & World Report featured Dr. Lyles.
In 2022, Dr. Lyles led Keystone through its second uncontested charter renewal. The renewal runs from July 1, 2022, through June 30, 2027. It allows authorized enrollment to grow from 700 to as many as 1,000 students over the term, subject to annual performance, attendance, enrollment, and discipline requirements. The district granted a 300-student increase that year, and the school began offering an Algebra I Summer Bridge Program.
1,000
Max authorized enrollment, up from 700
+300
Students granted in 2022
2nd
Uncontested charter renewal
The Campus Today
2024 & Beyond
Growth then reached the campus itself. In early 2024, Keystone finished a 10,000-square-foot addition with eight classrooms, an art studio, outdoor instructional space, a staff lounge, a custodial office, and student and staff restrooms. Staff and students began using the expanded facilities in 2025. The campus now combines the restored Mary Disston School, the 2017 building, and the 2024 addition. In 2026, the school ended the year with a record 25 media mentions.
Today Keystone serves kindergarten through eighth grade at 4521 Longshore Avenue. It is a Philadelphia public charter school accredited by the Middle States Association of Colleges and Schools. Its mission stresses rigorous academics, with a concentration on science and mathematics supported by integrated technology. It also offers the arts, social-emotional development, community service, and service learning. Dr. Lyles remains CEO, and a six-member Board of Trustees is listed for 2026–27. Keystone is in the district’s 2026–27 charter-renewal cohort, and its next formal review is scheduled for 2027.
The Keystone Timeline
2007–2027
2007
School established as Planet Abacus Charter School
2012
Dr. Claudia Lyles named interim CEO; first charter renewal granted
2013
Dr. Lyles named CEO
2014
School renamed Keystone Academy Charter School
2016
Keystone Foundation purchases the Longshore Avenue property, including the former Mary Disston School
2017
Keystone relocates to the new Longshore Avenue campus
2018
School District of Philadelphia names KACS a Peer Leader (based on 2016–17 performance); mayor recognizes KACS as a “Most Improved School”
2019
“Idea Box” engineering space completed
2021
Dr. Lyles featured nationally in U.S. News & World Report
2022
Second uncontested charter renewal; 300-student increase granted; Algebra I Summer Bridge Program begins