It took me forever to find this list. I figured I’d post it prominently just so nobody else had to go through the same trouble.
This is a CSV file of zip codes, main city within the zip code (by the USPS’s reckoning) and the two-letter state abbreviation.
Download directly: download zipcode list as csv file
Or view this full post to see a short sample from the complete list.ZIP,City,ST
00501,Holtsville,NY
00544,Holtsville,NY
00601,Adjuntas,PR
00602,Aguada,PR
00603,Aguadilla,PR
00604,Aguadilla,PR
00605,Aguadilla,PR
00606,Maricao,PR
00610,Anasco,PR
00611,Angeles,PR
00612,Arecibo,PR
00613,Arecibo,PR
00614,Arecibo,PR
00616,Bajadero,PR
00617,Barceloneta,PR
00622,Boqueron,PR
00623,Cabo Rojo,PR
00624,Penuelas,PR
00627,Camuy,PR
00631,Castaner,PR
..................
48730,East Tawas,MI
48731,Elkton,MI
48732,Essexville,MI
48733,Fairgrove,MI
48734,Frankenmuth,MI
48735,Gagetown,MI
48736,Gilford,MI
48737,Glennie,MI
48738,Greenbush,MI
48739,Hale,MI
48740,Harrisville,MI
48741,Kingston,MI
48742,Lincoln,MI
48743,Long Lake,MI
48744,Mayville,MI
48745,Mikado,MI
48746,Millington,MI
48747,Munger,MI
48748,National City,MI
48749,Omer,MI
48750,Oscoda,MI
48754,Owendale,MI
48755,Pigeon,MI
48756,Prescott,MI
48757,Reese,MI
48758,Richville,MI
48759,Sebewaing,MI
48760,Silverwood,MI
48761,South Branch,MI
48762,Spruce,MI
48763,Tawas City,MI
48764,Tawas City,MI
48765,Turner,MI
48766,Twining,MI
48767,Unionville,MI
48768,Vassar,MI
48769,Tuscola,MI