| ZIP Codes: | 51 ZIP Codes (34 Standard, 14 PO Box, 3 Unique) [See All] |
| Area Codes: | 227 / 240 / 410 / 443 / 667 |
| Timezone: | Eastern (GMT -05:00) |
| Local Time: | 2:12:28 PM |
| Population: | 811,235 [See All] |
| FIPS: | 24005 |
| CBSA: | Baltimore-Columbia-Towson, MD |
| Land Area: | 589 sq mi |
| Water Area: | 28 sq mi |
| Coordinates: | 39.4267, -76.6084 |
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811,235 residents live across 51 ZIPs covering 589 sq mi, served by 44 distinct USPS-recognized cities.
Population moved from 781,726 to 811,166 from 2014 to 2024 — a +3.8% change. 29 ZIPs gained residents, 11 lost.
The county's wealthiest ZIP 21131 (Phoenix, $197,619 median) and poorest ZIP 21222 (Dundalk, $64,141) are 17.5 miles apart — a 3.1× income gap across local geography.
Median home values vary 3.2× across this county — from $215,900 in 21222 (Dundalk) to $686,000 in 21131 (Phoenix).
Density varies 1600× across the county — from 135 people/sq mi in 21111 (Monkton) to 215,265 in 21252 (Towson).
Educational attainment ranges from 14.9% bachelor's+ in 21222 (Dundalk) to 73.9% in 21131 (Phoenix) — the breadth of educational profiles across the area.
Within Maryland, this is the #3 most populous of 24 counties and ranks #9 for median household income .
On the national stage, Baltimore County is the #79 most populous US county , ranks #97 for income .
Hosts 3 single-entity Unique ZIPs: 21250Univ Of Md Baltimore County ; 21252Towson State University ; and 21065Cockys Ht Vly .
Weighted by population, the typical household earns about $94,616 across the county — reflecting what a typical resident sees, not a simple ZIP average.
41.3% of adults age 25+ hold a bachelor's degree or higher (233,233 of 564,953 reporting).
34 Standard delivery, 14 PO Box only, 3 single-entity Unique ZIPs serve this county.
5 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.
3 ZIP codes in this county serve a single facility — typically theme parks, universities, large corporations, airports, or government complexes.
Median household income spans 3.1× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 21234 | Parkville | Standard | 66,334 | $83,517 | 14.1 | -4.3% |
| 21117 | Owings Mills | Standard | 62,816 | $101,831 | 29.2 | 8.8% |
| 21222 | Dundalk | Standard | 59,407 | $64,141 | 18.2 | 7.9% |
| 21228 | Catonsville | Standard | 50,492 | $112,656 | 15.3 | 1.9% |
| 21207 | Gwynn Oak | Standard | 47,099 | $67,060 | 9.9 | -3.7% |
| 21221 | Essex | Standard | 43,487 | $67,340 | 22.2 | 8.2% |
| 21220 | Middle River | Standard | 42,824 | $81,817 | 31.1 | 6.0% |
| 21236 | Nottingham | Standard | 39,514 | $95,149 | 9.9 | 5.0% |
| 21093 | Lutherville Timonium | Standard | 39,100 | $125,528 | 22.0 | 4.6% |
| 21244 | Windsor Mill | Standard | 38,208 | $85,114 | 14.8 | 4.1% |
| 21208 | Pikesville | Standard | 37,276 | $90,131 | 13.0 | 11.2% |
| 21227 | Halethorpe | Standard | 34,907 | $85,986 | 10.7 | 0.9% |
| 21136 | Reisterstown | Standard | 32,088 | $118,500 | 61.1 | -4.2% |
| 21237 | Rosedale | Standard | 31,425 | $91,693 | 10.9 | 3.6% |
| 21133 | Randallstown | Standard | 31,398 | $80,480 | 9.1 | 1.0% |
| 21030 | Cockeysville | Standard | 25,827 | $89,015 | 24.1 | 2.0% |
| 21286 | Towson | Standard | 21,853 | $93,808 | 8.2 | 9.0% |
| 21204 | Towson | Standard | 19,845 | $99,606 | 6.7 | -2.1% |
| 21128 | Perry Hall | Standard | 15,501 | $128,069 | 6.1 | 6.6% |
| 21219 | Sparrows Point | Standard | 9,565 | $110,438 | 17.9 | 7.1% |
| 21120 | Parkton | Standard | 7,440 | $162,052 | 42.7 | 4.0% |
| 21131 | Phoenix | Standard | 7,141 | $197,619 | 22.0 | -2.0% |
| 21152 | Sparks Glencoe | Standard | 6,459 | $121,350 | 24.7 | 9.3% |
| 21013 | Baldwin | Standard | 5,610 | $171,354 | 15.5 | 12.0% |
| 21087 | Kingsville | Standard | 5,537 | $129,188 | 14.7 | -0.8% |
| 21252 | Towson | Unique | 4,865 | — | 0.0 | 81.3% |
| 21111 | Monkton | Standard | 4,714 | $136,304 | 35.0 | 11.2% |
| 21162 | White Marsh | Standard | 4,639 | $157,813 | 9.1 | 19.6% |
| 21057 | Glen Arm | Standard | 4,386 | $145,924 | 16.3 | 11.1% |
| 21155 | Upperco | Standard | 3,313 | $123,158 | 21.3 | 28.6% |
| 21053 | Freeland | Standard | 2,929 | $89,497 | 21.6 | -11.2% |
| 21250 | Baltimore | Unique | 2,834 | — | 0.2 | -6.3% |
| 21082 | Hydes | Standard | 626 | $145,571 | 6.0 | 77.8% |
| 21153 | Stevenson | PO Box | 456 | $220,179 | 2.4 | 45.7% |
| 21052 | Fort Howard | PO Box | 409 | $77,300 | 0.5 | 46.6% |
| 21071 | Glyndon | PO Box | 404 | $213,500 | 0.1 | -25.3% |
| 21156 | Upper Falls | Standard | 204 | — | 1.1 | -45.3% |
| 21051 | Fork | Standard | 172 | $232,721 | 0.4 | -36.8% |
| 21023 | Butler | PO Box | 66 | $84,474 | 0.0 | — |
| 21105 | Maryland Line | PO Box | 36 | — | 0.0 | 125.0% |
| 21031 | Hunt Valley | Standard | 26 | — | 0.9 | 4.0% |
| 21285 | Towson | PO Box | 3 | — | 0.0 | — |
| 21284 | Towson | PO Box | — | — | 0.0 | — |
| 21139 | Riderwood | PO Box | — | — | 0.0 | — |
| 21022 | Brooklandville | PO Box | — | — | 0.0 | — |
| 21094 | Lutherville Timonium | PO Box | — | — | 0.0 | — |
| 21027 | Chase | PO Box | — | — | 0.0 | — |
| 21282 | Pikesville | PO Box | — | — | 0.0 | — |
| 21020 | Boring | PO Box | — | — | 0.0 | — |
| 21065 | Hunt Valley | Unique | — | — | 0.0 | — |
| 21092 | Long Green | PO Box | — | — | 0.0 | — |