You can use Tool #902 Update Membership/Account Reason Codes to update the following:
  • You can change the Membership Open Reason Code on a current, active membership (alters the NEWACT field on MASTER).
  • You can change the Membership Closed Reason Code on a closed membership (alters the NEWACT field on MSHIST).
  • You can change the Account Open Reason Code on a current, active sub-account (alters the RSNCDEOPN field on MEMBERx).
  • You can change the Account Closed Reason Code on a closed sub-account (alters the RSNCDECLO field on ACHISTx). 
You cannot, however, change the Account Open Reason Code on a closed sub-account. 

Also, because the membership record (MASTER / MSHIST) shares a single NEWACT field, whatever Membership Open Reason Code was in the NEWACT field in the MASTER table when the membership was closed will have been replaced by a Membership Closed Reason Code stored in that same field in the MSHIST table.