NumberResearch Membership · Data 09/20/2026

Recent thousands-block assignments

0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

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 586
LEVEL 3 COMMUNICATIONS, LLC - MI 59
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2020-01-16 586-800-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2019-05-06 586-900-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2019-05-06 586-900-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2019-05-06 586-900-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2019-04-08 586-666-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2019-04-08 586-666-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2019-04-08 586-666-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2017-09-07 586-238-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2014-08-06 586-200-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2014-07-21 586-625-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ARMADA MI
2014-04-10 586-221-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2014-03-04 586-430-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 RICHMOND MI
2013-10-03 586-522-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2013-09-09 586-200-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2013-05-30 586-554-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WARREN MI
2011-12-09 586-690-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2011-12-01 586-684-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEWBALTIMR MI
2011-08-31 586-480-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WARREN MI
2010-11-16 586-690-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2010-11-03 586-480-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WARREN MI
2010-11-01 586-335-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2008-09-10 586-884-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 UTICA MI
2008-07-15 586-239-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2007-11-20 586-447-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2007-10-15 586-439-0XXX 0000–0999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2007-04-09 586-438-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WARREN MI
2006-05-17 586-276-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WARREN MI
2006-01-16 586-648-1XXX 1000–1999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEWBALTIMR MI
2005-12-06 586-501-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2005-12-06 586-501-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2005-11-17 586-646-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 NEW HAVEN MI
2005-08-15 586-439-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI
2005-08-15 586-580-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 UTICA MI
2005-08-15 586-580-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 UTICA MI
2005-03-21 586-623-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROMEO MI
2005-03-21 586-623-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROMEO MI
2005-03-18 586-486-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2005-03-18 586-486-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2005-03-18 586-486-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2005-02-21 586-697-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WASHINGTON MI
2005-02-21 586-697-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WASHINGTON MI
2005-02-17 586-630-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2005-02-17 586-630-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2005-02-17 586-649-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 MT CLEMENS MI
2005-01-05 586-838-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 WARREN MI
2004-12-10 586-782-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2004-12-10 586-782-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2004-12-10 586-782-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2004-12-10 586-782-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 CENTERLINE MI
2004-11-10 586-218-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - MI 6120 ROSEVILLE MI

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.