Huntsville, AL ZIP Codes: All 24, and the 7 That Aren't Neighborhoods

All 24 ZIP codes, and why fewer than half are standard delivery routes

Madison County holds all 24 of the ZIP codes USPS assigns to "Huntsville, AL," per this site's source data, a cleaner map than Atlanta's or Denver's county-straddling lists, and one Huntsville shares with Fresno. Counting by county alone hides how the codes actually function, though: split by delivery type, zip-codes.com's tally puts only 11 of Huntsville's 24 on standard carrier routes, against 7 reserved for a single high-volume address and 6 assigned to PO boxes, a smaller standard-route share than Fresno manages with 19 out of 58, despite Huntsville's list running well under half Fresno's length.

Two of the 7 unique codes belong to a credit union and a university

Unique ZIP codes exist for a single organization or address large enough to justify its own code, rather than sharing one with its surrounding neighborhood, and Huntsville's public record identifies two by name. 35893 is assigned to Redstone Federal Credit Union at 220 Wynn Drive, Alabama's largest credit union and one of the 20 largest federal credit unions in the country by membership. 35899 belongs to the University of Alabama in Huntsville, which anchors Cummings Research Park, the second-largest research park in the United States and the fourth-largest in the world by size. Because unique codes like these are administrative rather than residential, the Census Bureau doesn't publish population figures for either one, unlike the standard codes on the same list.

The other 5 unique codes on Huntsville's list aren't identified by a single named tenant in public postal directories the way 35893 and 35899 are, so this page doesn't guess at who holds them.

35808 carries Huntsville's name but sits mostly on an Army post

35808 is the one code on this list that blurs the line between city and federal installation. USPS and GeoNames both file it under "Huntsville, AL," and it's the code this site's source data returns for the city. But independent ZIP-boundary trackers city-data.com and zipdatamaps.com both describe its actual footprint as centered on Redstone Arsenal, the Army post that hosts the Army's Aviation and Missile Command, the Missile Defense Agency, and NASA's Marshall Space Flight Center. The arsenal's own post office, at 3710 Aerobee Road, operates under that same 35808 code.

That's a different kind of blurred line than the one on this site's Cincinnati list, where a defunct IRS processing center got its own dedicated code: 35808 is an active federal installation folded into a city's ordinary ZIP list rather than carved out as an obviously administrative code like 35893 or 35899.

256 split from 205 in 1998, then added an overlay 12 years later

Huntsville's area code, 256, didn't exist before March 23, 1998, when regulators split it off from 205, which had covered the entire state of Alabama since the North American Numbering Plan assigned area codes nationwide in 1947. 256 took the northern and northeastern part of the state (Huntsville, Decatur, Florence, and Gadsden), while 205 kept Birmingham and the rest; a permissive dialing period let callers use either code through September 28, 1998, while phone systems, pagers, and fax machines were reprogrammed.

No second split followed 256's creation. What came next, on July 10, 2010, was an overlay: 938, layered onto the same 256 footprint rather than carving out a new slice of territory, so a new Huntsville-area number can land on either code while every number already dialing 256 stays put. Twelve years passed between the split and that overlay, roughly the interval this site's Toronto area's 437 overlay records between each of that region's own overlay additions, and a small fraction of the 74 years Washington, D.C. waited for its first one.