Mobile Accuracy and Precision Broadband Act of 2018 or the MAP Broadband Act This bill directs the Federal Communications Commission (FCC) to extend the period of the process under which a person may challenge the initial determination that an area is ineligible for Mobility Fund Phase II support (i.e., the challenge process) until November 27, 2018. The Mobility Fund is a program within the FCC's Universal Service Fund that provides monetary support for the deployment of mobile broadband service. Phase II of the fund provides monetary support over a 10-year period for mobile voice and broadband coverage in mostly rural areas. The FCC must: (1) publicly disclose handsets (i.e., phones) approved for use in the challenge process to assist consumers in exploring potential challenges, (2) publish online monthly updates on the number of entities that it has approved to participate in the challenge process and the percentage of the total area initially determined to be ineligible for Mobility Fund Phase II support that has been challenged, and (3) publish annual updates on whether the deployment of mobile wireless service is being expanded in rural areas due to Mobility Fund Phase II support.