ZIP CodesZIP codes in Boone County, Iowa
Boone County, Iowa has 9 ZIP codes in this list, from 50031 to 50223. They cover 7 places, among them Boone, Beaver, Boxholm and Luther.
| ZIP code | Place | Land area (sq mi) | Map point |
|---|---|---|---|
| 50031 | Beaver | 0.2 | 42.039, -94.144 |
| 50036 | Boone | 192 | 42.069, -93.878 |
| 50037 | Boone | no area | 42.060, -93.880 |
| 50040 | Boxholm | 1.5 | 42.171, -94.105 |
| 50099 | Boone | no area | 42.060, -93.880 |
| 50152 | Luther | 0.4 | 41.939, -93.837 |
| 50156 | Madrid | 88.5 | 41.884, -93.845 |
| 50212 | Ogden | 132 | 42.035, -94.006 |
| 50223 | Pilot Mound | 29.0 | 42.160, -94.010 |
Where Boone County is
Going by the map points of its ZIP codes, Boone County sits near the middle of Iowa. Its codes spread over about 20 miles from north to south and 16 miles from east to west. The two codes farthest apart are 50040 (Boxholm) and 50156 (Madrid), about 24 miles from each other in a straight line. The nearest neighbours on the ZIP code map, measured between the middle points of their codes, are Greene County (20 miles), Story County (22 miles), Hamilton County (26 miles) and Dallas County (26 miles).
The first three digits
The codes of Boone County begin with 500 (5 codes), 501 (2 codes) and 502 (2 codes). The first three digits of a ZIP code name the mail sorting area it belongs to. The prefix 500 is shared with 23 other counties, such as Adair County, Audubon County and Carroll County, and has 68 codes in all.
How much ground the codes cover
The Census Bureau draws an area for 7 of the 9 codes. Together they come to about 443 square miles of land (1,148 sq km). The largest is 50036 (Boone) with 192 square miles, and the smallest is 50031 (Beaver) with 0.2. The middle-sized code here covers 29.0 square miles; the middle value for all of Iowa is 48.0. These areas follow ZIP code delivery routes, so their total is not the official size of Boone County; a code can reach across its border. 2 codes have no mapped area: 50037 (Boone) and 50099 (Boone). Codes like these are normally for post office boxes or one large building.
By number of ZIP codes, Boone County ranks 42nd among the 99 counties and county-level areas of Iowa (equal counts share a rank), with 9 of the 1,055 codes in the state list.
Writing an address in Boone County
The name of the county is not written in a United States address. The last line is the postal city, the letters IA and the ZIP code:
- Boone, IA 50036 (one of 3 codes for Boone; the street decides which)
- Beaver, IA 50031
- Boxholm, IA 50040
Questions about Boone County ZIP codes
What is the ZIP code for Boone, IA?
Boone has 3 ZIP codes in Boone County: 50036, 50037, 50099. Which one applies depends on the street address.
Do all ZIP codes in Boone County start with the same digits?
No. They use 3 different three-digit beginnings; the most common is 500, on 5 of the 9 codes.
Which ZIP code in Boone County covers the most land?
50036 (Boone), at about 192 square miles in the Census Bureau's 2024 figures.
Using this list
- In an address, the ZIP code comes last, after the city and the two-letter state: Beaver, IA 50031.
- Tap a ZIP code to open it in the look-up, with a copy button for the address line.
- A code can cross a county line, and one town can have several codes. The table shows the main place of each code.
- "No area" means the Census Bureau draws no area for that code. Such codes are usually for post office boxes or a single building.
Places and counties: GeoNames. Areas: U.S. Census Bureau, 2024 ZIP Code Tabulation Areas. Checked in November 2026. This site is not connected with the United States Postal Service; for mailing, confirm the address with USPS.