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County ZIP codes · Tennessee · FIPS 47105

Loudon County, TN ZIP Codes

Loudon County, Tennessee has 8 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026), all residential. 5 of the residential ones lie mainly in Loudon County and 3 mainly in a neighboring county; 7 cross the county line. Median household income ranges from $53,605 in 37874 (Sweetwater) to $100,711 in 37772 (Lenoir City) (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Loudon County?

37737 · Friendsville: $82k37742 · Greenback: $89k37771 · Lenoir City: $67k37772 · Lenoir City: $101k37774 · Loudon: $88k37846 · Philadelphia: $72k37874 · Sweetwater: $54k37885 · Vonore: $79k378853777437874378463777137742377723773737737 · Friendsville: $82k37742 · Greenback: $89k37771 · Lenoir City: $67k37772 · Lenoir City: $101k37774 · Loudon: $88k37846 · Philadelphia: $72k37874 · Sweetwater: $54k37885 · Vonore: $79k378853777437874378463777137742377723773737737 · Friendsville: $82k37742 · Greenback: $89k37771 · Lenoir City: $67k37772 · Lenoir City: $101k37774 · Loudon: $88k37846 · Philadelphia: $72k37874 · Sweetwater: $54k37885 · Vonore: $79k3788537774378743784637771377423777237737
The residential ZIP codes of Loudon County (whole outlines, including the parts in neighboring counties), shaded by median household income in national fifths (ACS 2020-2024). <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $66,938 and $87,718.

They carry 7 postal town names: Loudon, Lenoir City, Sweetwater, Friendsville, Greenback, Vonore, Philadelphia.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 8 residential ZIP codes in Loudon County

5 ZIP codes lie mainly in Loudon County; 3 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Loudon County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
37774 Loudon 21,784 247 $88k $365k 86%
37771 Lenoir City 18,042 360 $67k $280k 75%
37772 Lenoir City 14,646 379 $101k $430k 100%
37742 Greenback 7,046 143 $89k $302k 68%
37846 Philadelphia 4,579 63 $72k $202k 43%

Partly in Loudon County

Residential ZIP codes mainly in another county that reach at least 1% into Loudon County, by their share here
In this county
37874 Sweetwater 16,567 161 $54k $191k 9%
37737 Friendsville 7,081 265 $82k $321k 6%
37885 Vonore 6,271 43 $79k $335k 2%

Download the 8 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

7 ZIP codes of Loudon County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Loudon County and in the neighboring counties
ZIPIn LoudonElsewhere
3777486%Roane County 13%; Monroe County 1%
3777175%Roane County 25%
378749%Monroe County 70%; McMinn County 21%
377376%Blount County 94%
3774268%Blount County 32%
378852%Monroe County 98%
3784643%Roane County 39%; Monroe County 15%; McMinn County 4%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

Which first three digits do Loudon County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Loudon County's ZIP codes use 2 prefixes: 377 and 378.

Three-digit prefixes of Loudon County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Loudon County's
PrefixSectional centerHereAll codes
377 Knoxville, TN (SCF 377) 5 53
378 Knoxville, TN (SCF 377) 3 67

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.