Several carriers that were awarded Mobility Fund Phase I (MF1) support in 2012’s Auction 901 have been afforded relief on their construction deadlines to deploy 3G or 4G mobile wireless networks in eligible unserved areas. One group of carriers that had initially committed to build 3G networks within three years had requested to update and modify their projects and timetables to deploy 4G networks instead. MF1 awards for 4G deployments have four-year construction deadlines. Upon review of the carriers’ revised project descriptions, the FCC’s wireline and wireless bureaus decided to extend the carriers’ construction deadlines to the four-year deadline. A second group of carriers that committed to build 3G networks within three years sought limited extensions of their construction deadlines after encountering unusual delays beyond their control. Recognizing that the carriers demonstrated conscientious efforts to complete their construction as expeditiously as possible under unusual circumstances and did so within a relatively short time beyond the deadline, the bureaus found there was good cause to grant the carriers the limited extensions they had requested.