Residential delivery area · Tennessee
ZIP Code 37031: Castalian Springs, TN
ZIP code 37031 uses the postal name Castalian Springs, Tennessee and lies mostly in Sumner County (78% of its land) with the rest in Trousdale County (Census 2020 ZIP-county file). About 3,900 people live there (Census Bureau, ACS 2020-2024). Median household income is $98,114 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Hartsville/Trousdale County (22%) and Castalian Springs (15%); 63% is outside any Census place.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Castalian Springs · its only residential ZIP
- County
- Sumner County (78%); Trousdale County (22%)
- Census places
- Hartsville/Trousdale County (22%); Castalian Springs (15%) census-designated place
- Metro area
- Nashville-Davidson--Murfreesboro--Franklin, TN
- House district
- TN-6 119th Congress
- State
- Tennessee
- Time zone
- Central
- Land area
- 38.3 sq mi · 103 people per sq mi
Where is ZIP code 37031?
37031 centers on 36.377°, -86.301° and covers 38.3 square miles of land plus 1.8 of water. It borders 4 ZIP codes: 37087, 37066, 37074, 37022.
The map draws ZIP code areas only. For the streets inside 37031, 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 37031 compare with the rest of Sumner County?
| Measure | 37031 | In Sumner County | In TN |
|---|---|---|---|
| People (ACS 2020-2024) | 3,926 | 9th of 9 | 337th of 636 |
| Median household income | $98k | 3rd of 8 | 37th of 425 |
| Median home value | $353k | 5th of 9 | 80th of 436 |
Its median household income is higher than in 80% of U.S. residential ZIP codes, and it is denser than 54% 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 37031?
The 2020 Census counted 4,296 people in 37031; the ACS, which samples households over 2020-2024, estimates 3,926. Between the 2010 and 2020 censuses its population grew 15.7% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 3,926±537 (90% margin)
- 2020 Census count
- 4,296+15.7% since 2010 (3,712)
- Households
- 1,707
- Median age
- 53.5
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 37031?
Of the 3,926 people the ACS estimates in 37031, 15.2% are under 18 and 20.0% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (89.5%).
- Under 1815.2%
- 18 to 6464.7%
- 65 and older20.0%
- White, not Hispanic89.5%
- Hispanic or Latino4.4%
- Other or two or more3.1%
- Black, not Hispanic2.7%
- Asian, not Hispanic0.4%
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 37031 earn?
Median household income is $98,114 (ACS 2020-2024), the 3rd highest of the 8 ranked ZIP codes in Sumner County. It is not measurably different from 2015-2019 ($90,363 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $98,114±$12,443
- Income per person
- $44,690
- Below the poverty line
- 8.3%
- Unemployed (of the labor force)
- 0.7%
- Adults 25+ with a bachelor's degree
- 21.2%
- Adjusted gross income per tax return, 2022
- $76,0302,160 returns; wages 74% 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 37031?
FHFA's house price index for 37031, built from repeat sales and appraisals of the same homes, rose 128% from 2015 to 2025 and rose 56% from 2020 to 2025, and moved −0.8% in 2025.
- Median home value (owners' estimate)
- $352,600
- Median gross rent
- –
- Homes owned by their occupants
- 94.1%
- Housing units
- 1,804
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 37031?
38 business establishments had a location in this ZIP code in 2023, 12 more than in 2018; the most are in construction (ZIP Code Business Patterns).
- Construction11
- Retail trade5
- Other services (except public administration)5
- Administrative and support and waste management and remediation services4
- Health care and social assistance3
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 37031?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 37087 | Lebanon | 56,655 | $82k | 8.0 mi |
| 37066 | Gallatin | 64,650 | $82k | 8.7 mi |
| 37074 | Hartsville | 10,932 | $72k | 8.9 mi |
| 37022 | Bethpage | 5,728 | $79k | 9.5 mi |
| 37151 | Riddleton | 457 | $102k | 15.1 mi (near) |
| 37057 | Dixon Springs | 1,016 | $79k | 15.3 mi (near) |
| 37186 | Westmoreland | 10,709 | $60k | 15.8 mi (near) |
| 37122 | Mount Juliet | 68,492 | $113k | 17.2 mi (near) |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.