In recent years, the private and public sectors have increased investments in medical diagnostics for low- and middle-income countries (LMICs). Despite these investments, numerous barriers prevent the adoption of existing diagnostics and discourage the development and introduction of new diagnostics in LMICs. In the late 1990s, the global vaccine community had similar challenges, as vaccine coverage rates stagnated and the introduction of new vaccines was viewed as a distraction to delivering existing vaccines. To address these challenges, the international community came together and formed the Global Alliance for Vaccines Initiative (GAVI). Sixteen years after the formation of GAVI, we see evidence of a healthier global vaccine landscape. We discuss how GAVI’s four guiding principles (product, health systems strengthening, financing and market shaping) might apply to the advancement of medical diagnostics in LMICs. We present arguments for the international community and existing organizations to establish a Global Alliance for Medical Diagnostics Initiative (GAMDI).