The National Institutes of Health (NIH) is seeking applications for the renewal of the MACS/WIHS Combined Cohort Study (MWCCS) through a limited competition funding opportunity (RFA-HL-26-009). The initiative supports up to 13 Clinical Research Sites (CRS) for a six-year project period (2026–2032). The MWCCS is an epidemiological study of HIV in U.S. adults, focusing on middle-aged and older populations living with HIV (PLWH) and comparable individuals without HIV (PLWOH). The study employs a populomics approach to examine health determinants across multiple scales, aiming to address disparities, comorbidities, and quality of life in this population. This effort aligns with NIH’s strategic plans for HIV research and the White House initiative "Ending the HIV Epidemic (EHE)."

Eligible applicants are limited to institutions previously funded under RFA-HL-19-008. The total estimated funding for fiscal year 2026 is $34.17 million, supporting individual CRS budgets up to $2.4 million annually. Each CRS must continue to follow a deeply phenotyped cohort of approximately 5,700 participants and expand data collection efforts based on NIH scientific priorities, including cardiovascular health, aging, mental health, cancer, substance use, and more.

Applicants must demonstrate the capability to address operational and scientific objectives, including participant retention, data collection, quality assurance, and collaboration within the MWCCS. They must also propose specific aims for operational and investigational activities, ensuring alignment with the NIH's scientific priorities for HIV-related research. The program emphasizes using multidisciplinary and community-engaged approaches, integrating social and structural determinants of health to reduce disparities.

Applications must include a leadership plan detailing roles for multiple principal investigators (mPIs) and a strategy for site-specific contributions to both operational and investigational aims. Budget justifications must reflect planned activities and compensation for participants and staff. A Joint Unified Modular Protocol (JUMP) will guide data collection for study visits, focusing on efficiency and participant well-being.

Key dates include a letter of intent due 30 days before the application deadline of May 2, 2025. Peer review is scheduled for November 2025, with advisory council review in January 2026, and awards starting in April 2026. Applications must conform to NIH submission guidelines and demonstrate adherence to ethical and regulatory standards.

This funding opportunity offers a significant chance to advance research on HIV-associated comorbidities, aging, and health disparities. Interested applicants should review the detailed guidance and ensure their applications align with the rigorous scientific and operational goals of the MWCCS.