From a large dataset, I am interested in counting the member ID and categorizing the number of visits based upon the DOS_Start (SAS Enterprise 7.1 (7.100.0.1966) (64-bit).   There are occasions where there are different claim numbers that have the same DOS.   An example in this data is that the member 0001 had multiple claims in the ER for DOS_Start of 4/11/17; however, I only want to count this as one visit to the ER for this analysis.   In this newest iteration of code, I'm able to get the member ID correct but not the visit. When the member ID is 0002, the visit counter should reset to 1; however, it is continuing to auto-increment as if it is still member ID 0001.   Thank you in advance for your help! - Karen    Current code:   PROC SORT DATA=WORK.SAMPLE OUT=WORK.SORTED;   BY MEMBER_AMISYS_NBR DOS_Start;  RUN; DATA WANT;   SET WORK.SORTED;   BY MEMBER_AMISYS_NBR DOS_Start;    Format DOS_Start MMDDYY10.;   RETAIN MEMID VISIT 0;   IF FIRST.MEMBER_AMISYS_NBR THEN MEMID = MEMID + 1;  /* autoincrement based upon new Amisys # */    IF FIRST.DOS_START THEN DO;   VISIT=VISIT+1; /* this works to increment visits based upon date */   END; RUN;   Current Output: MEMBER_AMISYS_NBR CLAIM_NBR DOS_Start MCC1 MCC2 MEMID VISIT 0001 12 03/15/2017 Primary Care Primary Care 1 1 0001 12 03/15/2017 Primary Care Primary Care 1 1 0001 84 03/16/2017 Hospital Outpatient Outpatient- Other 1 2 0001 84 03/16/2017 Hospital Outpatient Outpatient- Other 1 2 0001 43 03/17/2017 Hospital Outpatient Outpatient- Other 1 3 0001 66 04/11/2017 Emergency Room ED Other 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 22 04/11/2017 Emergency Room Emergency Room 1 4 0001 44 04/11/2017 Emergency Room ED Other 1 4 0002 6 08/18/2017 Primary Care Primary Care 2 5 0002 6 08/18/2017 Primary Care Primary Care 2 5 ... View more