ZIP codes in Maryland by county
Maryland has 478 ZIP codes in its 24 counties. 77 of them cross a county line and 1 cross into a neighboring state. Baltimore County has the most, 57.
By the All Map Tools Team
- ZIP codes
- 478
- With 1% or more of their land in the state
- Counties
- 24
- 11 with a page of their own below
- Cross a county line
- 77
- 1% or more of their land in another county
- Cross a state line
- 1
- 1% or more of their land in another state
- County with the most
- 57
- Baltimore County
- Most populated ZIP
- 20906
- 70,595 people · Aspen Hill
ZIP codes per county in Maryland
- 9–15
- 16–18
- 19–32
- 33–57
Counties and their ZIP codes
| County | Population (2025) | ZIP codes | Shared |
|---|---|---|---|
| Allegany County | 66,848 | 16 | 4 |
| Anne Arundel County | 603,380 | 42 | 9 |
| Baltimore city | 569,997 | 32 | 17 |
| Baltimore County | 847,650 | 57 | 28 |
| Calvert County | 94,484 | 14 | 4 |
| Caroline County | 34,116 | 10 | 4 |
| Carroll County | 176,677 | 15 | 12 |
| Cecil County | 107,131 | 15 | 0 |
| Charles County | 176,593 | 25 | 5 |
| Dorchester County | 33,628 | 18 | 2 |
| Frederick County | 302,883 | 35 | 11 |
| Garrett County | 28,370 | 12 | 4 |
| Harford County | 266,446 | 24 | 6 |
| Howard County | 339,183 | 25 | 11 |
| Kent County | 19,565 | 9 | 2 |
| Montgomery County | 1,074,582 | 53 | 11 |
| Prince George's County | 970,374 | 40 | 8 |
| Queen Anne's County | 54,448 | 16 | 6 |
| Somerset County | 24,973 | 11 | 2 |
| St. Mary's County | 116,692 | 27 | 2 |
| Talbot County | 38,238 | 16 | 2 |
| Washington County | 157,731 | 20 | 4 |
| Wicomico County | 106,899 | 16 | 2 |
| Worcester County | 54,459 | 12 | 3 |
Every ZIP code in Maryland, by county
A ZIP code that crosses a county line appears in each county it has 1% or more of its land in.
- Allegany County (16)
- 21502, 21521, 21524, 21529, 21530, 21532, 21539, 21540, 21542, 21543, 21545, 21555, 21557, 21560, 21562, 21766
- Anne Arundel County (42)
- 20701, 20711, 20714, 20724, 20733, 20736, 20751, 20754, 20755, 20758, 20764, 20765, 20776, 20778, 20779, 20794, 21012, 21032, 21035, 21037, 21054, 21056, 21060, 21061, 21076, 21077, 21090, 21108, 21113, 21114, 21122, 21140, 21144, 21146, 21225, 21226, 21240, 21401, 21402, 21403, 21405, 21409
- Baltimore city (32)
- 21201, 21202, 21205, 21206, 21207, 21208, 21209, 21210, 21211, 21212, 21213, 21214, 21215, 21216, 21217, 21218, 21222, 21223, 21224, 21225, 21226, 21227, 21229, 21230, 21231, 21233, 21234, 21236, 21237, 21239, 21251, 21287
- Baltimore County (57)
- 21013, 21023, 21030, 21031, 21043, 21051, 21052, 21053, 21057, 21071, 21074, 21082, 21085, 21087, 21093, 21102, 21104, 21105, 21111, 21117, 21120, 21128, 21131, 21133, 21136, 21152, 21153, 21155, 21156, 21161, 21162, 21163, 21204, 21206, 21207, 21208, 21209, 21210, 21212, 21215, 21219, 21220, 21221, 21222, 21224, 21227, 21228, 21229, 21234, 21236, 21237, 21239, 21244, 21250, 21252, 21285, 21286
- Calvert County (14)
- 20615, 20629, 20639, 20657, 20676, 20678, 20685, 20688, 20689, 20714, 20732, 20736, 20754, 20758
- Caroline County (10)
- 21629, 21632, 21636, 21639, 21640, 21641, 21649, 21655, 21657, 21660
- Carroll County (15)
- 21048, 21074, 21102, 21104, 21136, 21155, 21157, 21158, 21757, 21771, 21776, 21784, 21787, 21791, 21797
- Cecil County (15)
- 21901, 21902, 21903, 21904, 21911, 21912, 21913, 21914, 21915, 21917, 21918, 21919, 21920, 21921, 21930
- Charles County (25)
- 20601, 20602, 20603, 20607, 20611, 20612, 20613, 20616, 20617, 20622, 20625, 20632, 20637, 20640, 20645, 20646, 20658, 20659, 20661, 20662, 20664, 20675, 20677, 20693, 20695
- Dorchester County (18)
- 19973, 21613, 21622, 21626, 21627, 21631, 21632, 21634, 21643, 21648, 21659, 21664, 21669, 21672, 21675, 21677, 21835, 21869
- Frederick County (35)
- 20842, 20871, 21701, 21702, 21703, 21704, 21705, 21710, 21714, 21716, 21717, 21718, 21719, 21727, 21754, 21755, 21757, 21758, 21762, 21769, 21770, 21771, 21773, 21774, 21776, 21777, 21778, 21780, 21783, 21787, 21788, 21790, 21791, 21793, 21798
- Garrett County (12)
- 21520, 21521, 21523, 21531, 21532, 21536, 21538, 21539, 21541, 21550, 21561, 21562
- Harford County (24)
- 21001, 21005, 21009, 21010, 21013, 21014, 21015, 21017, 21028, 21034, 21040, 21047, 21050, 21078, 21082, 21084, 21085, 21087, 21111, 21130, 21132, 21154, 21160, 21161
- Howard County (25)
- 20701, 20723, 20759, 20763, 20777, 20794, 20833, 21029, 21036, 21042, 21043, 21044, 21045, 21046, 21075, 21076, 21104, 21163, 21723, 21737, 21738, 21771, 21784, 21794, 21797
- Kent County (9)
- 21610, 21620, 21635, 21645, 21650, 21651, 21661, 21667, 21678
- Montgomery County (53)
- 20705, 20707, 20777, 20812, 20814, 20815, 20816, 20817, 20818, 20832, 20833, 20837, 20838, 20839, 20841, 20842, 20850, 20851, 20852, 20853, 20854, 20855, 20860, 20861, 20862, 20866, 20868, 20871, 20872, 20874, 20876, 20877, 20878, 20879, 20880, 20882, 20886, 20889, 20892, 20894, 20895, 20896, 20899, 20901, 20902, 20903, 20904, 20905, 20906, 20910, 20912, 21771, 21797
- Prince George's County (40)
- 20601, 20607, 20608, 20613, 20623, 20705, 20706, 20707, 20708, 20710, 20712, 20715, 20716, 20720, 20721, 20722, 20735, 20737, 20740, 20742, 20743, 20744, 20745, 20746, 20747, 20748, 20762, 20769, 20770, 20771, 20772, 20774, 20781, 20782, 20783, 20784, 20785, 20903, 20904, 20912
- Queen Anne's County (16)
- 21607, 21617, 21619, 21620, 21623, 21628, 21638, 21640, 21644, 21649, 21651, 21657, 21658, 21666, 21668, 21679
- Somerset County (11)
- 21817, 21821, 21822, 21824, 21838, 21851, 21853, 21866, 21867, 21871, 21890
- St. Mary's County (27)
- 20606, 20609, 20618, 20619, 20620, 20621, 20622, 20624, 20626, 20628, 20630, 20634, 20636, 20650, 20653, 20656, 20659, 20660, 20667, 20670, 20674, 20680, 20684, 20686, 20687, 20690, 20692
- Talbot County (16)
- 21601, 21612, 21624, 21625, 21647, 21652, 21653, 21654, 21657, 21662, 21663, 21665, 21671, 21673, 21676, 21679
- Washington County (20)
- 21711, 21713, 21715, 21719, 21722, 21733, 21734, 21740, 21742, 21746, 21750, 21756, 21758, 21767, 21779, 21780, 21781, 21782, 21783, 21795
- Wicomico County (16)
- 21801, 21804, 21810, 21814, 21822, 21826, 21830, 21837, 21840, 21849, 21850, 21856, 21861, 21865, 21874, 21875
- Worcester County (12)
- 21804, 21811, 21813, 21822, 21829, 21841, 21842, 21851, 21862, 21863, 21864, 21872
Neighboring states
Tools for Maryland
Sources
- U.S. Census Bureau, 2020 ZCTA to County, ZCTA to Place and ZCTA to Census Tract Relationship Files (and the 2022 County Subdivision to ZCTA file for Connecticut). Public domain.
- U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, table B01003 (population of each ZIP code, census tract and Connecticut town). Public domain.
- U.S. Census Bureau, Vintage 2025 Population Estimates (county population) and 2025 Gazetteer Files (land area and interior point of each ZIP code). Public domain.
- U.S. Census Bureau, Cartographic Boundary Files: ZCTAs 2020 and counties 2025, 1:500,000; county adjacency file 2025. Public domain.
How we count. ZIP codes here are the Census Bureau’s ZIP Code Tabulation Areas (ZCTAs), the areas it draws to match USPS ZIP codes; ZIPs with no area of their own (PO boxes, single buildings) aren’t included. A ZIP can cross county lines: “Land in the county” is the exact share of its land inside, from the Census relationship files. “Residents in the county” is the whole ZIP for those entirely inside; for shared ones it’s an estimate, spreading the people of each census tract over the land it shares with the ZIP. Population: ACS 2020–2024. Methodology.
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