San Juan Municipio
Puerto Rico · County seat: San Juan · Active county or equivalent
FIPS code 72127 is San Juan Municipio, Puerto Rico. With a population of 340,903 (2022 ACS estimate), it ranks #1 in Puerto Rico and #209 nationally. San Juan Municipio is part of the San Juan-Bayamón-Caguas, PR. The state FIPS code for Puerto Rico is 72. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
72127
Population
340,903
2022 ACS · #209 nationally
Density
7,124.4/mi²
people per sq mile
Land Area
48
sq miles
Urban/Rural
Metro — 1M+ population
RUCC 1
How This FIPS Code Works
The 5-digit FIPS code 72127 is formed by combining the 2-digit state identifier 72 (Puerto Rico) with the 3-digit county identifier 127. Together they uniquely identify San Juan Municipio in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 72127
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 72127.
Median Household Income
$26,111
ACS B19013_001E
Poverty Rate
39.5%
ACS B17001 (below poverty level)
Median Age
45.0
ACS B01002_001E
Metropolitan Area
Adjacent Counties (7)
Counties that share a border with San Juan Municipio. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 72127.
Federal Datasets Using Code 72127
FIPS code 72127 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 72127 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.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:127",
"in": "state:72",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [San Juan Municipio, Puerto Rico, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '72127';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '72'
AND county_fips = '127';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 72127 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "72",
county = "127",
year = 2022
)ZIP Codes in San Juan Municipio
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 San Juan Municipio. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 00927 | 100.0% |
| 00901 | 100.0% |
| 00906 | 100.0% |
| 00907 | 100.0% |
| 00909 | 100.0% |
| 00911 | 100.0% |
| 00912 | 100.0% |
| 00913 | 100.0% |
| 00915 | 100.0% |
| 00917 | 100.0% |
| 00918 | 100.0% |
| 00920 | 100.0% |
| 00921 | 100.0% |
| 00923 | 100.0% |
| 00925 | 100.0% |
| 00924 | 96.5% |
| 00926 | 83.5% |
| 00969 | 11.2% |
| 00966 | 8.0% |
| 00725 | 2.3% |
| 00976 | 2.2% |