The National Institutes of Health (NIH) is inviting applications for the Development of Biomarkers or Composite Biomarkers for Neurological and Neuromuscular Disorders through a phased grant mechanism (R61/R33). This funding opportunity aims to enhance the discovery and early evaluation of candidate biomarkers that can facilitate the clinical development of neurotherapeutics and improve clinical care decisions. The initiative emphasizes the importance of multidisciplinary collaboration and requires applicants to validate biomarkers in a phased approach, with the R61 phase focusing on proof of concept studies and the R33 phase on preliminary clinical validation. Interested applicants should note that the application deadline is January 7, 2028, and they can direct inquiries to NIH Grants Information at grantsinfo@nih.gov. For further details, applicants can refer to the full announcement available at https://grants.nih.gov/grants/guide/pa-files/PAR-25-024.html.