Broadband Permitting Modernization Act This bill modifies, and requires reports about, permitting requirements for broadband activities on federal lands. Specifically, the Department of the Interior and the Department of Agriculture (USDA) must report on communication use authorizations (i.e., authorizations to modify or locate communications facilities on public land administered by Interior or National Forest System land). Among other topics, the report must assess barriers to reviewing the authorizations and describe the process for prioritizing reviews. Interior and USDA must also each establish an online portal to manage the Form 299 (used to apply for rights to install, modify, or maintain a communications facility on federal real property) approval process. The National Telecommunications and Information Administration must (1) report to Congress every 60 days on the status of the portals until they are established, and (2) publish links to each established portal on its website. The bill also authorizes the delegation of federal environmental compliance for certain broadband projects to states and Indian tribes. Interior and USDA must establish a voluntary program whereby states or Indian tribes may conduct (subject to specified terms) environmental reviews for broadband projects within an operational right-of-way (i.e., all real property interests acquired for the construction or operation of a project) on land managed by Interior, National Forest System land, or Indian land. USDA and Interior shall also establish broadband permit streamlining teams to coordinate and expedite permitting decisions for broadband projects.