Monitor these closely. Usually you get denials for “Medical necessity” due to mismatched or missing diagnosis. Your payor might consider a particular CPT as medically necessary diagnosis for another related CPT.
There is no universal rule per se (unless you are dealing with Medicare/Medicaid that has NCDs).
You need to understand AND have a “ready to go” checklist per payer.
This checklist should have this intelligence to show you the medically necessary (deemed) CPT for the related CPT that you are submitting in the claim. You might even need to consult with your provider to get further information on this as well (since clinicals are out of your area of expertise).
Review the documentation, make sure that the documentation supports the diagnosis, then resubmit the claim.
Most importantly, keep building this internal database of yours.
The workflow you are using here (or modifying) is that the billing department analyzes the denials, forms buckets, then trains / informs the coders to make corrections upstream. This strategy allows you to reduce such denials moving forward.