thank so much for replying ....however i did use the set command to set the permanent merged file i created to a temporary file.  This is what I had in my code: LIBNAME nhisproj "P:\Project"; DATA nhisproj.NHIS2012perm;       set TMP1.NHIScombined2;       KEEP SEX     RACERPI2    AFD_FLG DOINGLWA     AGE_P BMI             FLA1AR          MOB_2R         MOB_3F                    FLSOCL                                          AFLHCA18     AFLHCA17 UB_SS                 AFLHCA13    ALHCA14A AFLHCA15; /*Subset variables*/ RUN; PROC PRINT DATA=NHISproj.NHIS2012perm; /*Print the small subset*/ RUN; and this works fine but then when i try to do anything with the variables like recode them or create new variables it does not work. ... View more