On the most recent SNF Open Door Forum, CMS clarified how to code the start and end of therapy. The MDS coding systems have the ability to simply copy everything over so that the MDS coordinators can change the items that need to be changed. The start and end of therapy dates will carry over until there is a new start and end of therapy. This pertains to both Part A and Part B start and end dates.
Please see the CMS clarification below:
CMS reiterated that the start and end date of therapy must be coded, even if there were no minutes of therapy. If there are no minutes of therapy, the latest start and end dates of therapy should be used.