ZIP Codes in Chico are divided up by the area of town where they are located. There are three residential ZIP Codes in Chico, one for Post Office boxes, and one for Chico State. The most recent addition to Chico's ZIP Codes is 95973, which served to break up the previously expansive 95926. The boundaries of the various residential codes are as follows:

• 95926: Central Chico - Bordered on the north by East Avenue, and to the south between the Aves and the Streets. The Aves are a part of 95926, the Streets are not.
• 95928: South Chico and West Chico and Downtown - Basically, everything in Chico that isn't a part of North or Central Chico would be a part of this area. It extends beyond the city limits to include areas around Dayton but not Durham, which has its own ZIP Code.
• 95973: North Chico - Everything north of East Avenue, including areas outside the city limits, hugging the Sacramento River quite a distance north.

The non-residential ZIP Codes in Chico are:

• 95927: Post Office Boxes share this ZIP Code.
• 95929: All of Chico State's campus addresses share this ZIP Code.

The USPS has a ZIP Code Lookup if you know an address but are unsure of the ZIP Code.