Why did a doctor bill me out of network at an in-network hospital?

A clinician who treats you at an in-network hospital or surgery center may be out of network, but under the No Surprises Act they may not bill you more than your in-network share unless you signed a valid consent form in advance (42 U.S.C. §§ 300gg-111(b) and 300gg-132; 45 CFR 149.120 and 149.420). That form is never valid for emergency medicine, anesthesia, pathology, radiology, lab work, neonatology, assistant surgeons, hospitalists or intensivists (42 U.S.C. § 300gg-132(b)(2); 45 CFR 149.420(b)).

How come I was billed out of network at an in-network hospital? — answered from the law, on provern.org