https://communities.sas.com/t5/SAS-Procedures/Copying-data-in-one-cell-to-an-empty-cell-while/m-p/56566#M15796 I have a SAS dataset that contains multiple records for many persons. Persons are identified by SSN. The data must be de-identified so I created a var named PerID and populated it with a random digit number using FIRST.SSN. Now I want to copy the value of PerID for each of the first SSNs to the remainder each SSN. Note that the number of records for each person may range from 1 to 20. Wed, 28 Jul 2010 14:47:57 GMT deleted_user 2010-07-28T14:47:57Z https://communities.sas.com/t5/SAS-Procedures/Copying-data-in-one-cell-to-an-empty-cell-while/m-p/56566#M15796 I have a SAS dataset that contains multiple records for many persons. Persons are identified by SSN. The data must be de-identified so I created a var named PerID and populated it with a random digit number using FIRST.SSN. Now I want to copy the value of PerID for each of the first SSNs to the remainder each SSN. Note that the number of records for each person may range from 1 to 20. Wed, 28 Jul 2010 14:47:57 GMT https://communities.sas.com/t5/SAS-Procedures/Copying-data-in-one-cell-to-an-empty-cell-while/m-p/56566#M15796 deleted_user 2010-07-28T14:47:57Z https://communities.sas.com/t5/SAS-Procedures/Copying-data-in-one-cell-to-an-empty-cell-while/m-p/56567#M15797 Hi:<BR /> It sounds like you've already discovered BY group processing and FIRST.byvar. If you check into the workings of the RETAIN statement, you will find your answer.<BR /> <A href="http://support.sas.com/documentation/cdl/en/lrdict/63026/HTML/default/viewer.htm#/documentation/cdl/en/lrdict/63026/HTML/default/a000214163.htm" target="_blank">http://support.sas.com/documentation/cdl/en/lrdict/63026/HTML/default/viewer.htm#/documentation/cdl/en/lrdict/63026/HTML/default/a000214163.htm</A><BR /> <BR /> cynthia Wed, 28 Jul 2010 14:59:47 GMT https://communities.sas.com/t5/SAS-Procedures/Copying-data-in-one-cell-to-an-empty-cell-while/m-p/56567#M15797 Cynthia_sas 2010-07-28T14:59:47Z