Helping American Victims Afflicted by Neurological Attacks Act of 2021 or the HAVANA Act of 2021 This bill specifically authorizes the Central Intelligence Agency, the Department of State, and other agencies to provide payments to agency personnel who incur brain injuries from hostilities while on assignment. Specifically, the bill allows agency personnel and their families to receive payments for brain injuries that are incurred (1) during a period of assignment to a foreign duty station; (2) in connection with war, insurgency, hostile acts, terrorist activity, or other agency-designated incidents; and (3) not as the result of willful misconduct. The bill's authority applies to injuries incurred before, on, or after the date of the bill's enactment. Agencies must submit classified reports on the bill's implementation, including the number of payments made and the amount of each payment. Since 2016, some intelligence, diplomatic, and other governmental personnel have reported experiencing unusual cognitive and neurological impairments while on assignment (particularly abroad), the source of which is currently under investigation. Symptoms were first reported by personnel stationed in Cuba and have since been collectively referred to as Havana Syndrome .