Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/ME/HIGHEST-DENSITY

Most Densely Populated ZIP Codes in Maine

What this measures. People per square mile of land area. Source: Census American Community Survey and Gazetteer, data release 2026-10-12.

# ZIP City County People per sq mi
1 04101 Portland Cumberland 9,088
2 04469 Orono Penobscot 4,130
3 04103 Portland Cumberland 3,131
4 04102 Portland Cumberland 2,881
5 04106 South Portland Cumberland 2,224
6 04064 Old Orchard Beach York 1,288
7 04415 Brownville Junction Piscataquis 1,280
8 04341 Coopers Mills Lincoln 1,273
9 04092 Westbrook Cumberland 1,209
10 04240 Lewiston Androscoggin 1,122
11 03911 York Harbor York 1,023
12 04489 Stillwater Penobscot 859
13 04063 Ocean Park York 834
14 04431 East Orland Hancock 788
15 03904 Kittery York 768
16 04346 Randolph Kennebec 754
17 04110 Cumberland Foreside Cumberland 711
18 04108 Peaks Island Cumberland 679
19 04096 Yarmouth Cumberland 675
20 04107 Cape Elizabeth Cumberland 650
21 04412 Brewer Penobscot 633
22 04006 Biddeford Pool York 619
23 04841 Rockland Knox 548
24 04072 Saco York 540
25 04005 Biddeford York 517
26 04057 North Bridgton Cumberland 499
27 04074 Scarborough Cumberland 484
28 04473 Orono Penobscot 483
29 04083 Springvale York 481
30 04011 Brunswick Cumberland 478
31 04066 Orrs Island Cumberland 464
32 04073 Sanford York 461
33 04401 Bangor Penobscot 448
34 04252 Lisbon Falls Androscoggin 447
35 04347 Hallowell Kennebec 442
36 04105 Falmouth Cumberland 435
37 04210 Auburn Androscoggin 415
38 04062 Windham Cumberland 411
39 04250 Lisbon Androscoggin 408
40 04359 South Gardiner Kennebec 400
41 04538 Boothbay Harbor Lincoln 400
42 04530 Bath Sagadahoc 392
43 04975 Shawmut Somerset 382
44 04038 Gorham Cumberland 362
45 03903 Eliot York 361
46 04901 Waterville Kennebec 354
47 04631 Eastport Washington 348
48 04021 Cumberland Center Cumberland 340
49 03907 Ogunquit York 338
50 04043 Kennebunk York 337

Showing the top 50 of 426 ZIP codes in Maine that have this figure . 04101 ranks 1st at 9,088, against 337 in 50th place.

Other rankings for Maine

Cite this page

zipcodes.pro. “Most Densely Populated ZIP Codes in Maine.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/me/highest-density

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