CMS stated in the MLN SE22002 CR 12734, Elimination of Certificates of Medical Necessity & Durable Medical Equipment Information Forms

• For services on or after January 1, 2023: Don’t submit CMN or DIF forms or their electronic claim data elements with the claims, or we’ll reject your claims and return them to you.

• For services before January 1, 2023: Submit CMN and DIF forms or their electronic claim data elements with the claims if required

Original release Date May 23, 2022  MLN SE22002 read the entire article: 
                                               CMS says Less Paperwork for DME Suppliers after Jan 2023!