Usa state zip codes

In areas without a regular postal route or no mail delivery, ZIP codes may not be defined or have unclear boundaries. The main issue is discussed above: there simply isn't always a clear geographic boundary for a ZIP code.

The Census Bureau and many other commercial services will try to interpolate the data to create polygons shapes using straight lines to represent the approximate area covered by a ZIP code, but none of these maps are official or entirely accurate.

They provide a very close approximation of the area covered by a ZIP code. You can easily notice some of the boundary issues when viewing our maps. Very rural areas aren't labeled as belonging to a ZIP code such as much of Nevada and Utah where there are few, if any, addresses to deliver mail.

If the address is on the same street as a ZIP code boundary on the map, be sure to search for the full street address to determine the ZIP code instead of relying on the map.

Their purpose is to convey statistical data about regions that are familiar to most citizens. As discussed above, it is difficult to precisely define a geographic area covered by a ZIP code. ZCTAs were developed to account for some of the difficulties in assigning an area to a ZIP code and to precisely define a geographic area.

In general, they are updated once every 10 years for the Census. The Census assigns an area to a ZCTA according to census blocks the smallest geographic unit used by the census. Imagine a city block that makes up a typical census block as pictured to the right. It is bounded on all 4 sides by portions of city streets that each have their own name and addresses. The issue is that census blocks almost always split down the middle of the street.

ZIP codes rarely do because that would require two postal workers delivering mail to that street - one for each side of the street. In the example, one mail carrier may deliver to 3 sides of the block via one ZIP code while another mail carrier delivers mail on the other street in a different ZIP code. When this happens, the Census Bureau will assign the entire block to a single ZCTA in this case, because the census block is the area that is precisely measured.

If you are getting very precise usually a matter of meters, not miles , census block boundaries near the edge of a ZIP code almost always split ZIP codes. The statistics provided by the Census Bureau can give insight into the demographics within the ZIP code.

For instance, see our ZIP code rankings. Remember that ZIP codes were made to make mail delivery easier. They weren't made to correspond to existing boundaries such as cities, counties, or even states.

If it is more efficient for a mail carrier to drive across a state line to deliver mail, the ZIP code "boundary" will cross the state lines.

ZIP codes don't usually cross state lines, but some do , , and are good examples. The edges of the boundaries commonly overlap.

For the purposes of our free zip code database by county downloads, we will commonly list either the most common region for the ZIP code or list multiple regions if several exist in the ZIP code. FL Georgia Ga. IL Indiana Ind. KS Kentucky Ky. KY Louisiana La. MD Massachusetts Mass. MA Michigan Mich. MI Minnesota Minn. MN Mississippi Miss. MS Missouri Mo. MO Montana Mont. MT Nebraska Nebr. NE Nevada Nev. NV New Hampshire N. NH New Jersey N. NJ New Mexico N. NM New York N. NY North Carolina N.

NC North Dakota N. OK Oregon Ore. OR Pennsylvania Pa. PA Rhode Island R. RI South Carolina S. SC South Dakota S. SD Tennessee Tenn. TN Texas Tex.