What is meant by the statement that the services of a medical assistant must be billed “incident to” the services of the delegating physician for the physician to be reimbursed for the medical assistant’s services under Medicare?
Legally, medical assistants work under direct/onsite provider (e.g., physician, nurse practitioner, physician assistant) supervision and authority in outpatient settings. Medical assistants do not have National Provider Identifier (NPI) numbers because they are not reimbursed directly by Medicare for their services. Rather, their services may only be billed and reimbursed incident to the services of the delegating provider.
Note the following from the Medicare Benefit Policy Manual:
Incident to a physician’s professional services means that the services or supplies are furnished as an integral, although incidental, part of the physician’s personal professional services in the course of diagnosis or treatment of an injury or illness. …
Auxiliary personnel means any individual who is acting under the supervision of a physician, regardless of whether the individual is an employee, leased employee, or independent contractor of the physician, or of the legal entity that employs or contracts with the physician. …
Thus, where a physician supervises auxiliary personnel to assist him/her in rendering services to patients and includes the charges for their services in his/her own bills, the services of such personnel are considered incident to the physician’s service if there is a physician’s service rendered to which the services of such personnel are an incidental part.
For more information, see my Public Affairs article from the March/April 2018 CMA Today: “Medicare CCM and TCM Programs: Defining Medical Assistants’ Roles and Services.”