53033 FipsDecoder
23019 County FIPS Code

Penobscot County

Maine · County seat: Bangor · Active county or equivalent

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FIPS code 23019 is Penobscot County, Maine. With a population of 152,640 (2022 ACS estimate), it ranks #3 in Maine and #442 nationally. Penobscot County is part of the Bangor, ME. The state FIPS code for Maine is 23. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.

County FIPS

23019

State FIPS

23

ME

Population

152,640

2022 ACS · #442 nationally

Density

44.9/mi²

people per sq mile

Land Area

3,397

sq miles

Urban/Rural

Metro — under 250K population

RUCC 3

How This FIPS Code Works

23 019
23 = State FIPS (Maine)
019 = County FIPS

The 5-digit FIPS code 23019 is formed by combining the 2-digit state identifier 23 (Maine) with the 3-digit county identifier 019. Together they uniquely identify Penobscot County in every US federal dataset. No two counties share the same 5-digit FIPS code.

Census ACS Data for FIPS 23019

From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 23019.

Median Household Income

$59,438

ACS B19013_001E

Poverty Rate

13.4%

ACS B17001 (below poverty level)

Median Age

42.4

ACS B01002_001E

Metropolitan Area

Adjacent Counties (6)

Counties that share a border with Penobscot County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 23019.

Federal Datasets Using Code 23019

FIPS code 23019 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.

Using FIPS Code 23019 in Code

Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.

Census ACS API — Python 23019
import requests

url = "https://api.census.gov/data/2022/acs/acs5"
params = {
    "get":  "NAME,B19013_001E,B01003_001E",
    "for":  "county:019",
    "in":   "state:23",
    "key":  "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json()  # [[header...], [Penobscot County, Maine, income, pop, ...]
SQL — filtering by county FIPS 23019
-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '23019';

-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '23'
  AND county_fips = '019';

-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 23019 is WRONG for this county
R — tidycensus 23019
library(tidycensus)

get_acs(
  geography = "county",
  variables = c(income = "B19013_001E", pop = "B01003_001E"),
  state     = "23",
  county    = "019",
  year      = 2022
)
Zero-padding reminder: FIPS codes must always be stored and compared as zero-padded strings. 23 (not 23) and 019 (not 19) — losing the leading zeros is one of the most common data-join bugs in federal datasets. Full guide →

ZIP Codes in Penobscot County

ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Penobscot County. Why FIPS ≠ ZIP →

ZIP Code % in county
04401 100.0%
04410 100.0%
04411 100.0%
04412 100.0%
04417 100.0%
04418 100.0%
04419 100.0%
04422 100.0%
04427 100.0%
04428 100.0%
04765 100.0%
04777 100.0%
04928 100.0%
04932 100.0%
04939 100.0%
04953 100.0%
04969 100.0%
04430 100.0%
04434 100.0%
04435 100.0%
04444 100.0%
04448 100.0%
04449 100.0%
04450 100.0%
04453 100.0%
04455 100.0%
04456 100.0%
04457 100.0%
04460 100.0%
04461 100.0%

Showing top 30 of 47 ZIP codes by residential address share.

Other Counties in Maine