PFAS Exposure Assessment and Documentation Act This bill requires the Department of Defense (DOD) to include in various health evaluations an assessment of whether a member of the Armed Forces has been exposed to perfluoroalkyl or polyfluoroalkyl substances, commonly referred to as PFAS. In addition, DOD must establish a task force to address the effects of the release of PFAS from DOD activities. The bill requires DOD to ensure that any periodic health assessment, physical assessment for recently separated members, pre-deployment medical examination, post-deployment medical examination, and post-deployment health reassessment provided to a member of the Armed Forces includes an evaluation of whether the member has been exposed to PFAS or was based or stationed at a military installation with a known or suspected release of PFAS during the period the member was there. If any of the evaluations result in a positive determination of potential exposure to PFAS, DOD must provide blood testing during the evaluation. DOD must pay for blood testing to determine and document potential exposure to PFAS for former members of the Armed Forces or family members of such members who lived at a location identified by DOD as having a known or suspected PFAS release during the individuals' residency. DOD must share results of the evaluations with the Department of Veterans Affairs and establish a registry of members of the Armed Forces who have been exposed to, or are suspected to have been exposed to, PFAS. Members may elect to be excluded from the registry.