ZIP Code 21150 is located in Simpsonville Maryland. 21150 is entirely within Howard County. Regionally, it is located in Metro Baltimore.
| ZIP Code Name | Simpsonville |
| Primary County | Howard County |
| ZIP Code Type | PO Box |
| Current Time | EDT |
| Coordinates | 39.18548965,-76.89625549 |
| Adjacent ZIP Codes | |
| Region | Metro Baltimore |
| Metropolitan/Micropolitan Stat Area | Baltimore-Columbia-Towson, MD |
| Time Zone | Eastern Daylight Time |
| IANA Timezone | America/New_York |
| US Congressional Districts in 21150 | |
| Maryland State Senate Districts in 21150 | |
| Maryland State House of Delegates Districts in 21150 |
| School Districts in 21150 | |
| Elementary Schools in 21150 | |
| Middle Schools in 21150 | |
| High Schools in 21150 |