https://www.fcc.gov/general/broadband-deployment-data-fcc-form-477

• All facilities-based broadband providers are required to file data with the FCC twice a year (Form 477) on where they offer Internet access service at speeds exceeding 200 kbps in at least one direction.  

• Fixed providers file lists of census blocks in which they can or do offer service to at least one location, with additional information about the service.*