Twenty-one years ago, the IEEE Mixed-Signal Test Workshop (IMSTW) was inaugurated as one of the main forums that bring together the test community to discuss ideas and views specifically for analog, mixed-signal, and RF circuits and systems. IMSTW was renamed in 2008 to IEEE Mixed- Signal, Systems, and Sensors Test Workshop (IMS3TW) and was expanded to include new topics that address sensors and sensor-based systems, as well as emerging devices and systems. In 2015, we returned to the original name IMSTW to celebrate the 20th anniversary.