20738 ZIP Code: Riverdale, Maryland

ZIP code 20738 is in Riverdale, Maryland, in Prince George's County. ZIP codes are mail delivery routes rather than mapped regions, so the code identifies a set of addresses the Postal Service serves together, not a district with fixed borders.

20738 is in Prince George's County, Maryland. A single ZIP code can straddle a county line, because mail routes were drawn for delivery efficiency and take no notice of county boundaries, so the county shown is the one the code is primarily associated with.

ZIP codes and telephone area codes are separate systems with different boundaries, so no ZIP code maps to exactly one area code. Maryland uses 6 geographic area codes: 227, 240, 301, 410, 443 and 667.

Riverdale, Maryland has 2 ZIP codes in this dataset, of which 20738 is one. Large cities are split across many codes so mail can be sorted by district, and the codes are usually numerically close to each other.

Yes. 20738 appears in the GeoNames postal-code dataset as an active US code assigned to Riverdale, Maryland. Codes that have been retired or never issued do not appear, which is why entering one on this site returns a not-found page rather than a blank record.

Because they are not boundaries. A ZIP code is a collection of mail routes, and a route is a line a carrier walks or drives, not an area. Any ZIP code map you have seen is somebody's approximation drawn around the addresses in a code, which is also why two ZIP code maps rarely agree with each other.

Yes, routinely. The Postal Service assigns a preferred city name to each code for addressing purposes, and that name often covers several neighbouring towns, unincorporated areas or a whole postal district. The place shown here is the one the source names for the code, not a claim that every address in it is inside that town's limits.