Definition*: Health care services or supplies needed to diagnose or treat an illness, injury, condition, disease or its symptoms and that meet accepted standards of medicine.
Any and all claims may be called into question and require a copy of medical records for professional review to determine if they meet standards of medical necessity. Recent examples of this may include:
Ex. 1: A patient was delivered in hospital and the delivering OB requests a 2 and 6 week follow-up. The OB bills 59410 for delivery and all postpartum care. The patient then sees a midwife for 2 days, 4 days, 1 week, and 4 week visits. The patient's insurance may request a letter of medical necessity that establishes why it was necessary to see the patient 4 additional times by a secondary provider for routine postpartum care.
While there are many arguments to be made about a higher level of patient care, common postpartum complications, mental health, etc. It is important that your charting and claim coding (ICD-10) reflect that. That way when your care is being evaluated, it is clear in the review that the claims and level of coding was in fact medically necessary in addition to the 2 and 6 weeks OB visits.
*https://www.healthcare.gov/glossary/medically-necessary/