I wonder if its a normal thing to not have the CPT code on the medical necessity form?
Can't say . . . the PCP's office might know . . . the person who coordinates and files claims, not the one who greets patients in the waiting room.
If the practice is "large" they will probably have a MOM (medical office manager), but most offices bundle the days claims and transfer them to an offsite claim manager. If the practice is owned by a hospital, they are the ones responsible for filing.
But initial coding should happen in the PCP office.
Have you seen the form? Is there a place for a CPT code, or HCPS code?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865623/