Residential delivery area · Maine
ZIP Code 04421: Castine, ME
ZIP code 04421 uses the postal name Castine, Maine and lies entirely in Hancock County (Census 2020 ZIP-county file). About 1,400 people live there (Census Bureau, ACS 2020-2024). Median household income is $113,750 (Census Bureau, ACS 2020-2024). By Census place, 20% of its land lies in Castine (a census-designated place); 80% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2021
- ZBP2023
- IRS2022
- Town
- Castine · its only residential ZIP
- County
- Hancock County
- Census places
- Castine census-designated place
- House district
- ME-2 119th Congress
- State
- Maine
- Time zone
- Eastern
- Land area
- 7.8 sq mi · 175 people per sq mi
- PO Box ZIPs
- 04420 also use the name Castine
Where is ZIP code 04421?
04421 centers on 44.409°, -68.816° and covers 7.8 square miles of land plus 12.2 of water. It borders 3 ZIP codes: 04617, 04642, 04476.
The map draws ZIP code areas only. For the streets inside 04421, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 04421 compare with the rest of Hancock County?
| Measure | 04421 | In Hancock County | In ME |
|---|---|---|---|
| People (ACS 2020-2024) | 1,362 | 12th of 41 | 228th of 426 |
| Median household income | $114k | 1st of 11 | 8th of 200 |
| Median home value | $604k | 1st of 18 | 9th of 242 |
Its median household income is higher than in 88% of U.S. residential ZIP codes, and it is denser than 61% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 04421?
The 2020 Census counted 1,320 people in 04421; the ACS, which samples households over 2020-2024, estimates 1,362. Between the 2010 and 2020 censuses its population fell 3.4% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 1,362±167 (90% margin)
- 2020 Census count
- 1,320−3.4% since 2010 (1,366)
- Households
- 352
- Median age
- 21.2
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 04421?
Of the 1,362 people the ACS estimates in 04421, 9.5% are under 18 and 19.9% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (84.4%).
- Under 189.5%
- 18 to 6470.6%
- 65 and older19.9%
- White, not Hispanic84.4%
- Other or two or more6.9%
- Hispanic or Latino5.0%
- Black, not Hispanic3.7%
- Asian, not Hispanic0.0%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 04421 earn?
Median household income is $113,750 (ACS 2020-2024), the highest of the 11 ranked ZIP codes in Hancock County. It rose from $76,432 in 2015-2019 (in 2024 dollars), a change larger than the surveys' margins of error.
- Median household income
- $113,750±$26,100
- Income per person
- $39,304
- Below the poverty line
- 14.1%
- Unemployed (of the labor force)
- 2.7%
- Adults 25+ with a bachelor's degree
- 74.5%
- Adjusted gross income per tax return, 2022
- $124,680350 returns; wages 47% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 04421?
- Median home value (owners' estimate)
- $603,500
- Median gross rent
- $1,105
- Homes owned by their occupants
- 80.4%
- Housing units
- 720
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 04421?
28 business establishments had a location in this ZIP code in 2023, 3 fewer than in 2018; the most are in accommodation and food services (ZIP Code Business Patterns).
- Accommodation and food services7
- Construction4
- Retail trade4
- Arts, entertainment, and recreation4
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 04421?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 04617 | Brooksville | 651 | $52k | 5.3 mi |
| 04642 | Harborside | 202 | $72k | 5.4 mi |
| 04476 | Penobscot | 1,154 | $63k | 7.4 mi |
| 04974 | Searsport | 2,655 | $64k | 7.0 mi (near) |
| 04981 | Stockton Springs | 2,575 | $78k | 7.3 mi (near) |
| 04848 | Islesboro | 636 | $88k | 9.1 mi (near) |
| 04650 | Little Deer Isle | 333 | $110k | 9.2 mi (near) |
| 04676 | Sedgwick | 1,130 | $73k | 9.9 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.
Which other ZIP codes use the name Castine?
1 more ZIP code carries the postal name Castine, ME without a residential delivery area: PO boxes at the post office, or a single organization with its own ZIP code. The Census Bureau publishes no figures for it.
| ZIP | County |
|---|---|
| 04420 | Hancock County |
Source: GeoNames postal codes (CC BY 4.0), downloaded 2026-10-09; a ZIP code with no Census ZCTA has no residential delivery area.