The National Institute of Environmental Health Sciences (NIEHS) is seeking a contractor to provide comprehensive chemistry research and development support for its Division of Translational Toxicology (DTT). The contractor will perform services including test article procurement, characterization, formulation, and analysis, as well as ADME/TK studies and in vitro toxicity screening. A single cost plus fixed-fee contract is anticipated, with a 12-month base period and nine option periods beginning on or about January 18, 2027. The solicitation will be available electronically within 15 calendar days of this notice, with proposals due on or about July 20, 2026. No budget amount or performance location is specified in this pre-solicitation notice.