Large companies are striving to increase their purchases from small, diverse-owned businesses (SDBs) — those that are 51% or more owned and operated by an individual or group that is part of a historically underrepresented or underserved group (e.g., women, racial minorities, veterans, LGBTQIA+, and people with disabilities). Despite their pledges, they are struggling to meet their goals. The practices of four federal agencies can help them make their programs more effective.