By merging the response data with the map data, you're making life more difficult than it has to be! If you leave the 'all' option off the proc gmap, then it will only draw the areas of the map= dataset that have a matching ID in the data= dataset. Therefore I think the following code will do what you're wanting: /* import census zip code map */ proc mapimport datafile="/folder/proj/&dir/&user/Notes/&prj/Data/tl_2013_us_zcta510.shp" out=zipdata; run; /* import a list of all Florida's zip codes */ Data FL_Zips; infile "/folder/proj/&dir/&user/Notes/&prj/Data/FL_Zips.csv" dlm=',' dsd firstobs=3; input Zipcode : $5.; format zipcode $5.; run; /* make sure the id variable is named the same in both datasets */ Data FL_Zips; set Data FL_Zips; ZCTA5CE10=Zipcode; run; pattern1 v=s c=gray; proc gmap data=FL_Zips map=Zipdata2 /* all */; id ZCTA5CE10; choro segment / levels=1 nolegend; run; This little gmap paper I'm working on might also have some tips you can use... http://robslink.com/SAS/book1/Chapter_05_Maps.pdf ... View more