The Department of Veterans Affairs amends its adjudication regulations to implement provisions of the Sergeant First Class Heath Robinson Honoring our Promise to Address Comprehensive Toxics Act of 2022, Public Law 117-168 (PACT Act). The statute amended procedures applicable to claims based on toxic exposure and modified or established presumptions of service connection related to toxic exposure. Pursuant to the Act, VA removes the manifestation period requirement and the minimum compensable evaluation requirement from Gulf War claims based on undiagnosed illness and medically unexplained chronic multi-symptom illnesses. VA is also expanding the definition of a Persian Gulf Veteran and update the list of locations eligible for a presumption of exposure to toxic substances, chemicals, or hazards based on Gulf War service. To implement additional provisions of the Act, VA is also codifying the procedure for determining when examinations and medical nexus opinions are required for claims based on toxic exposure.