This is a GSA Schedule solicitation for reference laboratory services to provide medical laboratory testing for diagnosis, prevention, treatment, and health assessment. The performance location is domestic, defined as the 48 contiguous states, Alaska, Hawaii, Puerto Rico, Washington, D.C., and U.S. territories, though offerors may be limited to specific geographic service areas based on licensing. Offerors must provide services in at least one state, comply with all state and federal licensing and accreditation requirements—including specific out-of-state permits for certain states—and cannot subcontract to circumvent these rules. All tests must be categorized under predefined Special Item Numbers (SINs), have CPT codes, and use FDA-cleared reagents or be classified as Laboratory Developed Tests (LDTs). The solicitation is for new items only, and the Trade Agreements Act applies, restricting services to U.S.-made or designated country end products.