In the years since opening, the school moved from being ranked one of the lowest-performing in Colorado to number 10th in the state (SAT Scores).

The board of directors wanted to expand, which resulted in the leasing and remodeling of the conjoining building and adding the first 5th grade class in fall of 2015.

A mass shooting occurred on school grounds on May 7, 2019, leaving one student dead and eight others injured.

In the fall of 2020, STEM purchased the neighboring building to house its P-TECH program (Grades 13 and 14) and the Business Offices for STEM School Highlands Ranch as well as the Charter Network Main Offices of KOSON Network of Schools.

The north side of the building has a recreation area with picnic tables where high school students can eat lunch.

A grand opening ceremony was held on February 1, 2023, and students got their first look at the new secondary gym, weight room, locker rooms, gender neutral bathroom, middle school commons, FRHS storage spaces, and grand entry way.

KOSON currently operates inside STEM School Highlands Ranch's P-TECH building, also known as the Charter Network Main Offices.

[10] Dr. Karen Johnson became CEO after Penny Euker's resignation,[11] however, in May, 2023, she announced her retirement from KOSON Schools.