If you need All
within a given radius, you may also try GeoEntities
, which is faster:
GeoEntities[GeoDisk[GeoPosition[{40.11, -88.24}], Quantity[5, "Miles"]], "ZIPCode"]
{Entity["ZIPCode", "61824"], Entity["ZIPCode", "61825"], Entity["ZIPCode", "61801"], Entity["ZIPCode", "61874"], Entity["ZIPCode", "61802"], Entity["ZIPCode", "61821"], Entity["ZIPCode", "61822"], Entity["ZIPCode", "61803"], Entity["ZIPCode", "61820"], Entity["ZIPCode", "61826"]}