| Unit/Library | Phone | ||
| AA&PG Branch Library | 202.633.8232 |
| Acquisitions | 202.357.4532 |
| Administrative Services Office (ASO) | 202.633.7367 |
| Anacostia Branch Library | 202.610.3374 |
| CHNDM Branch Library | 212.849.8339 |
| Cullman Library (NHRB) | 202.633.0219 |
| Development Office | 202.786.2861 |
| Director's Office | 202.786.2866 |
| Freer Sackler Branch Library | 202.786.2936 |
| Hirshhorn Branch Library | 202.633.6764 |
| Information Systems Division (ISD) | 202.786.2861 |
| Interlibrary Loan Office | 202.786.2443 |
| MSC Branch Library | 301.238.3661 |
| Museums Information Library | 202.786.2443 |
| NASM Branch Library | 202.786.2835 |
| NMAfA Branch Library | 202.357.4879 |
| NMAH Branch Library | 202.357.4256 |
| NMAI Branch Library | 301.238.3038 |
| NMNH Branch Library | 202.357.1896 |
| NPM Branch Library | 202.633.8876 |
| NZP Branch Library | 202.673.4900 |
| Publications Office | 202.786.2861 |
| SERC Branch Library | 443.482.2286 |
| Shipping and Receiving Services | 202.786.9095 |
| SIL Annex | 202.357.1775 |
| Special Collections (Dibner) | 202.633.9102 |
| STRI Branch Library | 507.212.8147 |