The FCC’s Wireless Telecommunications Bureau (Bureau) has denied a request filed in 2016 by TerreStar Corporation (TerreStar) to waive the FCC’s performance requirement to demonstrate “substantial service” on its 1.4 GHz Band spectrum (including the paired 1392-1395 MHz and 1432-1435 MHz bands and unpaired 1390-1392 MHz band) that it acquired in 2007 and 2008. TerreStar specifically requested a three-year waiver or extension of its 2017 substantial service performance requirement (until April 23, 2020) to enable commercial wireless medical telemetry on its 1.4 GHz Band spectrum nationwide and argued that it could not construct its planned WiMAX network due to interference threats to Wireless Medical Telemetry Service (WMTS) operations and other entities in adjacent bands. TerreStar instead wishes to modify its deployments of medical telemetry services in various bands. However, the Bureau found that TerreStar was on notice of the possible effects of adjacent band incumbency and had known or should have known how this could impact its deployment plans. Moreover, the Bureau notes that TerreStar’s waiver request did not come until 2016 and that TerreStar “made little effort to actually implement and deploy a service” for much of its license term, despite TerreStar being tied up in a bankruptcy proceeding. As a result of the Bureau’s waiver denial and TerreStar’s lack of a timely substantial service demonstration, TerreStar’s 1.4 GHz licenses are subject to automatic termination.