All assignees
800 prefixes in 410 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 410-500 | BALTIMORE | 6855 | — | Yes |
| 410-501 | ARBUTUS | 829J | 2005-06-28 | Yes |
| 410-502 | BALTIMORE | 9212 | — | — |
| 410-503 | ELKRIDGE | 9212 | — | — |
| 410-504 | PIKESVILLE | 9212 | — | Yes |
| 410-505 | ELLICOTTCY | 9212 | — | Yes |
| 410-506 | ELKTON | 9212 | — | Yes |
| 410-507 | ANNAPOLIS | 6395 | — | — |
| 410-508 | GLENBURNIE | 9212 | — | Yes |
| 410-509 | WATERLO236 | 8697 | — | — |
| 410-510 | FORK | 7325 | — | Yes |
| 410-511 | XXXXXXXXXX | MULT | — | — |
| 410-512 | TOWSON | 9212 | — | Yes |
| 410-513 | PARKVILLE | 7325 | — | Yes |
| 410-514 | SEVERN | 9212 | — | Yes |
| 410-515 | FORK | 9212 | — | — |
| 410-516 | BALTIMORE | 9212 | — | Yes |
| 410-517 | REISTERSTN | 9212 | — | Yes |
| 410-518 | SEVERNA PK | 9212 | — | Yes |
| 410-519 | SEVERN | 9212 | — | — |
| 410-520 | OCEAN CITY | 9212 | — | Yes |
| 410-521 | RANDALLSTN | 9212 | — | — |
| 410-522 | BALTIMORE | 9212 | — | Yes |
| 410-523 | BALTIMORE | 9212 | — | — |
| 410-524 | OCEAN CITY | 9212 | — | — |
| 410-525 | BALTIMORE | 9212 | — | Yes |
| 410-526 | REISTERSTN | 9212 | — | — |
| 410-527 | COCKEYSVL | 9212 | — | — |
| 410-528 | BALTIMORE | 9212 | — | Yes |
| 410-529 | PARKVILLE | 9212 | — | — |
| 410-530 | CATONSVL | 4036 | — | Yes |
| 410-531 | COLUMBIA | 9212 | — | — |
| 410-532 | BALTIMORE | 9212 | — | — |
| 410-533 | ANNAPOLIS | 4036 | — | — |
| 410-534 | BALTIMORE | 9212 | — | Yes |
| 410-535 | PRINCEFRCK | 9212 | — | — |
| 410-536 | ARBUTUS | 9212 | — | Yes |
| 410-537 | BALTIMORE | 9212 | — | Yes |
| 410-538 | FORK | 9212 | — | Yes |
| 410-539 | BALTIMORE | 9212 | — | — |
| 410-540 | ELKRIDGE | 9212 | — | — |
| 410-541 | SEVERNA PK | 9212 | — | Yes |
| 410-542 | BALTIMORE | 9212 | — | — |
| 410-543 | SALISBURY | 9212 | — | — |
| 410-544 | SEVERNA PK | 9212 | — | — |
| 410-545 | BALTIMORE | 9212 | — | — |
| 410-546 | SALISBURY | 9212 | — | — |
| 410-547 | BALTIMORE | 9212 | — | — |
| 410-548 | SALISBURY | 9212 | — | — |
| 410-549 | SYKESVILLE | 9212 | — | — |
| 410-550 | BALTIMORE | 9212 | — | — |
| 410-551 | SEVERN | 9212 | — | — |
| 410-552 | SYKESVILLE | 9212 | — | Yes |
| 410-553 | GLENBURNIE | 9212 | — | Yes |
| 410-554 | BALTIMORE | 9212 | — | — |
| 410-555 | DIR ASST | MULT | — | — |
| 410-556 | CHURCHHILL | 9212 | — | Yes |
| 410-557 | FORK | 9212 | — | Yes |
| 410-558 | BALTIMORE | 9212 | — | Yes |
| 410-559 | PIKESVILLE | 7325 | — | Yes |
| 410-560 | TOWSON | 9212 | — | Yes |
| 410-561 | TOWSON | 9212 | — | Yes |
| 410-562 | ANNAPOLIS | 4036 | — | Yes |
| 410-563 | BALTIMORE | 9212 | — | — |
| 410-564 | ELKRIDGE | 7325 | — | Yes |
| 410-565 | ARBUTUS | 7591 | — | Yes |
| 410-566 | BALTIMORE | 9212 | — | — |
| 410-567 | ELKRIDGE | 7228 | — | Yes |
| 410-568 | COCKEYSVL | 7325 | — | Yes |
| 410-569 | EDGEWOOD | 9212 | — | — |
| 410-570 | ANNAPOLIS | 4036 | — | — |
| 410-571 | ANNAPOLIS | 9212 | — | Yes |
| 410-572 | SALISBURY | 9212 | — | Yes |
| 410-573 | ANNAPOLIS | 9212 | — | — |
| 410-574 | ESSEX | 9212 | — | — |
| 410-575 | FORK | 9212 | — | Yes |
| 410-576 | BALTIMORE | 9212 | — | — |
| 410-577 | PIKESVILLE | 9212 | 2005-05-10 | Yes |
| 410-578 | BALTIMORE | 9212 | — | — |
| 410-579 | ELKRIDGE | 9212 | — | — |
| 410-580 | PIKESVILLE | 9212 | — | — |
| 410-581 | PIKESVILLE | 9212 | — | — |
| 410-582 | GLENBURNIE | 9212 | — | Yes |
| 410-583 | TOWSON | 9212 | — | Yes |
| 410-584 | COCKEYSVL | 9212 | — | Yes |
| 410-585 | BALTIMORE | 9212 | — | Yes |
| 410-586 | PRINCEFRCK | 9212 | — | — |
| 410-587 | ARBUTUS | 7229 | — | Yes |
| 410-588 | BEL AIR | 9212 | — | Yes |
| 410-589 | BRYNPKLNCM | 7591 | — | Yes |
| 410-590 | GLENBURNIE | 9212 | — | — |
| 410-591 | BALTIMORE | 6395 | — | — |
| 410-592 | FORK | 9212 | — | Yes |
| 410-593 | FORK | 9212 | — | Yes |
| 410-594 | WOODLAWN | 9212 | — | — |
| 410-595 | GLENBURNIE | 7591 | — | Yes |
| 410-596 | WESTMINSTR | 6395 | — | — |
| 410-597 | WOODLAWN | 9212 | — | — |
| 410-598 | BALTIMORE | 6395 | — | — |
| 410-599 | CATONSVL | 4036 | — | — |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.