NumberResearchRecent thousands-block assignments
0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/25/2026
Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.
Most active assignees, all time — NPA 410
New assignments by month
Sep 2026
Aug 2026
Jul 2026
Jun 2026
May 2026
Apr 2026
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Dec 2025
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Oct 2025
| Assigned | Thousands-block | Last 4 digits | Status | Assignee | OCN | Rate center | State |
|---|---|---|---|---|---|---|---|
| 2019-06-27 | 410-801-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BALTIMORE | MD |
| 2018-05-01 | 410-657-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | PARKVILLE | MD |
| 2017-07-05 | 410-639-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | ROCK HALL | MD |
| 2017-03-27 | 410-801-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BALTIMORE | MD |
| 2017-03-27 | 410-801-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BALTIMORE | MD |
| 2017-03-27 | 410-801-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BALTIMORE | MD |
| 2015-08-18 | 410-874-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | ODENTON | MD |
| 2011-08-25 | 410-753-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | PIKESVILLE | MD |
| 2011-08-15 | 410-622-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BALTIMORE | MD |
| 2011-07-11 | 410-449-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | SOLOMONS | MD |
| 2010-10-08 | 410-656-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | NORTH EAST | MD |
| 2010-02-12 | 410-891-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | COCKEYSVL | MD |
| 2009-08-28 | 410-205-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | PIKESVILLE | MD |
| 2008-12-30 | 410-304-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | QUEENSTOWN | MD |
| 2008-12-09 | 410-352-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BISHOPVL | MD |
| 2008-12-09 | 410-482-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | GREENSBORO | MD |
| 2008-12-09 | 410-600-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BERLIN | MD |
| 2008-12-09 | 410-621-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | PRINCEANNE | MD |
| 2008-12-09 | 410-754-4XXX | 4000–4999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | FEDERALSBG | MD |
| 2008-12-09 | 410-928-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | MILLINGTON | MD |
| 2008-12-09 | 410-941-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | JARRETTSVL | MD |
| 2008-10-21 | 410-213-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | OCEAN CITY | MD |
| 2007-03-21 | 410-497-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | PARKVILLE | MD |
| 2007-01-16 | 410-861-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | WESTMINSTR | MD |
| 2007-01-12 | 410-441-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | ELKTON | MD |
| 2006-09-19 | 410-567-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | ELKRIDGE | MD |
| 2006-09-11 | 410-724-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WATERLO236 | MD |
| 2006-03-14 | 410-202-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | SALISBURY | MD |
| 2006-02-14 | 410-867-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | WEST RIVER | MD |
| 2005-12-13 | 410-697-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | MILLERSVL | MD |
| 2005-12-13 | 410-697-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | MILLERSVL | MD |
| 2005-11-15 | 410-630-1XXX | 1000–1999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CHASE | MD |
| 2005-11-15 | 410-630-8XXX | 8000–8999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CHASE | MD |
| 2005-07-19 | 410-630-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CHASE | MD |
| 2005-07-19 | 410-630-5XXX | 5000–5999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CHASE | MD |
| 2005-07-19 | 410-630-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CHASE | MD |
| 2005-07-19 | 410-630-7XXX | 7000–7999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | CHASE | MD |
| 2005-06-06 | 410-696-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | ELLICOTTCY | MD |
| 2005-04-08 | 410-809-2XXX | 2000–2999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BEL AIR | MD |
| 2005-01-13 | 410-558-6XXX | 6000–6999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | BALTIMORE | MD |
| 2004-07-07 | 410-200-9XXX | 9000–9999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | EASTON | MD |
| 2004-06-16 | 410-741-3XXX | 3000–3999 | Assigned | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | WEST RIVER | MD |
Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/25/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.