Many projects and programs rely upon test systems that were designed at the beginning of a program for on-going system support and maintenance. However, as programs are extended beyond their original life term, the equipment, including test systems, must undergo a modernization phase every few years in order to ensure continued support and maintenance of the system and its sub-assemblies. One of the major issues typically addressed by this upgrade phase is equipment obsolescence. As technology evolves, even programs (and test systems) that were originally designed for a long life term can face obsolescence issues. This paper reviews and compares the options available to program managers and test engineers facing test instrument obsolescence problems. Various options and tradeoffs are discussed including stocking of spare instruments, on-going maintenance & repair of current instrumentation, replacement through the used market, migration of existing test program sets (TPSs) to fit a new test system, replacement using similar products with software or hardware adapters, and replacement using same form-fit-function instrumentation.