ZIP 37663 falls in Sullivan County, Tennessee, where we hold 17,579 parcels measured as septic county-wide and 40,025 on sewer. We do not have a per-ZIP parcel count for this county, so this is the county total, not a count specific to ZIP 37663.
ZCTA 37663 is not entirely inside one county. Land-area share is from the 2020 Census ZCTA-to-county relationship file.
| County | Land in this ZIP | Documents held | On septic (county) | On sewer (county) |
|---|---|---|---|---|
| Sullivan County, Tennessee | 95% | — | 17,579 | 40,025 |
| Washington County, Tennessee | 5% | — | 17,810 | 24,967 |
Land-area overlap is from the 2020 Census Bureau ZCTA5-to-county relationship file, not an estimate of ours. Parcel and document counts are rows we hold, not a survey of every property in the ZIP. Last verified 2026-09-01.
We hold 17,579 parcels measured as septic for Sullivan County, Tennessee as a whole, not broken out by ZIP.
ZIP 37663 spans 2 counties: Sullivan County, Tennessee, Washington County, Tennessee.