Reliability testing often manifests device weaknesses and failure mechanisms. As new materials and structures are developed, creative and different testing is often necessary to determine reliability. We are developing an in-house reliability test system that will provide the necessary testing flexibility of HEMT devices so researchers can pinpoint defects and vulnerabilities. Using commercial off-the-shelf (COTS) power supplies and data acquisition equipment, a custom control system allows for many different tests: DC and RF, temperature, step/stress/recovery, high-speed pulse, and optical pumping, as well as combinations and automated sequencing of these tests. This flexibility allows for the creation of new test types as failure mechanisms are understood. The initial station will provide for the simultaneous, independent testing of 16 devices. This paper outlines the system design and capabilities, the motivation for the system, and some results from different tests.