@mjalvarez wrote: I get a blank (.) value for phase_1 using this code - data want; set have; array d (*) exam_date: ; array m (*) exam_measure: ; do i=dim(m) to 1 by -1; if m[i] le 5 then do; phase_1= d[i]; leave; end; end; run;     And the contents of the data set have is what? As I mentioned my code is untested because you did not provide an actual data set and you need to show which values actually create missing. I did say if none of the measure values are less than or equal to 5 then the phase variable will not be assigned.   Since your code above also uses different variable names then were implied by your example data that is something else to look at: the spelling of the variables. ... View more