Lake County Illinois is covered by a total of 37 ZIP Codes. There are 9 ZIP Codes in Lake County that extend into adjacent counties (Cook County, Kane County, Kenosha County, and Mchenry County). Of the ZIP codes within or partially within Lake County there are 33 Standard ZIP Codes, 1 Unique ZIP Codes and 2 PO Box ZIP Codes.
Click on the ZIP Codes in the interactive map to view more information. The map control in the upper right corner can be used to toggle map layers on and off. The red outline is the border of Lake County and can be turned on and off. Each type of postal code can also be turned on and off.