Does CMS require that the office hours be posted on the door?
As per the CMS DMEPOS Supplier Standards:
(D) Maintains a permanent visible sign in plain view and posts hours of operation. If the supplier's place of business is located within a building complex, the sign must be visible at the main entrance of the building or the hours can be posted at the entrance of the supplier.
Below is the link to the CMS DMEPOS Supplier Standards for your reference: