Project Summary/Abstract There is a need for human brain tissues in research to understand the impact HIV and co-morbid conditions such as opioid use disorders on the CNS. Since 1998, the National Neurological AIDS Bank (NNAB) has collected brain tissues and data from a cohort of HIV-seropositive (HIV+) participants. The purpose of this administrative supplement is to continue the ongoing work of NNAB after our no-cost time extension funds are expected to run out (estimated June 1, 2023) and before the contract is reviewed and negotiated (estimated late August, 2023. The funds will pay such costs as salary of investigators/staff, supplies, costs of tissue acquisition, processing, storage, and to ship tissue to approved researchers. Our samples and data can then continue to be available to investigators through our allocations process until the contracts are approved.