U S Government--postal Service, Prewitt Grants, NM 87020 Phone : (505) 876-2570 Business Category Government Offices-Federal Government Offices & Public Schools Post Office - Prewitt 1692 State Highway 122 Prewitt, NM 87045 Phone : (505) 876-2570 Post Office - Prewitt Business Category Post Offices Toll-Free           (800) ASK-USPS