Maryland Code, Health Occupations § 1-304

(a) A health care practitioner shall disclose the name of a referring health care practitioner on each request for payment or bill submitted to a third party payor, including nonprofit health plans and fiscal intermediaries and carriers, that may be responsible for payment, in whole or in part, of the charges for a health care service, if the health care practitioner knows or has reason to believe:

(b) A health care practitioner who knows or should have known of the practitioner's failure to comply with the provisions of this section shall be subject to disciplinary action by the appropriate licensing board.