R 418.10904 Procedure codes and modifiers.

Rule 904. (1) A healthcare service must be billed with procedure codes adopted from "Current Procedural Terminology (CPT®) 2025 Professional Edition" or "HCPCS 2025 Level II Professional Edition," as referenced in R 418.10107. Procedure codes from the CPT® code set are not included in these rules but are provided on the agency’s website at www.michigan.gov/leo/bureaus-agencies/wdca. Refer to "Current Procedural Terminology (CPT®) 2025 Professional Edition," as referenced in R 418.10107, for standard billing instructions, except where otherwise noted in these rules. A provider billing services described with procedure codes from "HCPCS 2025 Level II Professional Edition" shall refer to the publication as adopted by reference in R 418.10107, for coding information. (2) The following ancillary service providers shall bill codes from "HCPCS 2025 Level II Professional Edition," as adopted by reference in R 418.10107, to describe the ancillary services: (a) Ambulance providers. (b) Certified orthotists and prosthetists. (c) Medical suppliers, including expendable and durable equipment. (d) Hearing aid vendors and suppliers of prosthetic eye equipment. (e) A home health agency. (3) If a practitioner performs a procedure that cannot be described by 1 of the codes listed in the most recent publication titled “Current Procedural Terminology (CPT®)” or “HCPCS Level II,” as adopted in R 418.10107, the practitioner shall bill the unlisted procedure code. An unlisted procedure code must only be reimbursed when the service cannot be properly described with a listed code and the documentation supporting medical necessity includes all the following: (a) Description of the service. (b) Documentation of the time, effort, and equipment necessary to provide the care. (c) Complexity of symptoms. (d) Pertinent physical findings. (e) Diagnosis. (f) Treatment plan. (4) The provider shall add a modifier code, found in Appendix A of the CPT® codebook, as adopted by reference in R 418.10107, following the correct procedure code describing unusual circumstances arising in the treatment of a covered injury or illness. When a modifier code is applied to describe a procedure, a report describing the unusual circumstances must be included with the charges submitted to the carrier. (5) Applicable modifiers from table 10904 must be added to the procedure code to describe the type of practitioner performing the service. The required modifier codes for describing the practitioner are as follows: Table 10904 Modifier Codes (a) AA: When anesthesia services are performed personally by the anesthesiologist. (b) AD: When an anesthesiologist provides medical supervision for more than 4 qualified individuals, being either certified registered nurse anesthetists, certified anesthesiologist assistants, or anesthesiology residents. (c) AH: When a licensed psychologist bills a diagnostic service or a therapeutic service, or both. (d) AJ: When a certified social worker bills a therapeutic service. (e) AL: When a limited license psychologist bills a diagnostic service or a therapeutic service. (f) CO: When occupational therapy services are furnished in whole or in part by an occupational therapy assistant. (g) CQ: When physical therapy services are furnished in whole or in part by a physical therapy assistant. (h) CS: When a limited licensed counselor bills for a therapeutic service. (i) GF: When a non-physician, such as a nurse practitioner, advanced practice nurse, or physician assistant, provides services. (j) LC: When a licensed professional counselor performs a therapeutic service. (k) MF: When a licensed marriage and family therapist performs a therapeutic service. (l) ML: When a limited licensed marriage and family therapist performs a service. (m) TC: When billing for the technical component of a radiology service. (n) QK: When an anesthesiologist provides medical direction for not more than 4 qualified individuals, being either certified registered nurse anesthetists, certified anesthesiologist assistants, or anesthesiology residents. (o) QX: When a certified registered nurse anesthetist or certified anesthesiologist assistant performs a service under the medical direction of an anesthesiologist. (p) QZ: When a certified registered nurse anesthetist performs anesthesia services without medical direction.