Summary & Overview
CPT 01991: Anesthesia for Diagnostic or Therapeutic Nerve Block/Injection
CPT code 01991 denotes anesthesia services provided when an anesthesia professional manages the patient’s anesthetic care while another clinician performs a diagnostic or therapeutic nerve block or injection. This code is specific to procedures performed with the patient in positions other than prone or lying flat, and it captures the anesthesia component distinct from the procedure itself. Nationally, accurate use of this code affects billing clarity between anesthesia and procedural teams and impacts payment and encounter reporting for nerve block services.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, United Healthcare, and Medicare. Readers will find a concise overview of clinical context for anesthesia-provided nerve block support, how this code relates to common procedural scenarios, and its place alongside related injection and nerve block procedure codes. The publication also outlines typical sites of service and common clinical diagnoses associated with nerve block injections, offering clarity for coding, billing, and record classification. Policy and reimbursement benchmarking details are covered to help stakeholders understand coverage patterns and coding alignment across major national payers. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 01991 describes anesthesia services provided when a different clinician performs a diagnostic or therapeutic nerve block or injection. The anesthesiologist or anesthesia professional delivers anesthesia care while another provider performs the nerve block or injection procedure. The description specifies that the procedure is performed with the patient not in a prone position or lying flat, indicating positioning other than prone or supine.
Service type: Anesthesia for diagnostic or therapeutic nerve block/injection provided by an anesthesia professional while another clinician performs the procedure.
Typical site of service: Outpatient procedure areas or ambulatory surgery centers and hospital procedure rooms where nerve blocks and injection procedures are performed with the patient in a non-prone position.
Clinical & Coding Specifications
Clinical Context
A 52-year-old patient with chronic low back pain (M54.5) and radicular symptoms is scheduled for a diagnostic lumbar transforaminal epidural steroid injection performed by an interventional pain physician. An anesthesiologist is asked to provide monitored anesthesia care (MAC) for patient comfort and sedation during the injection. The anesthesiologist documents pre-procedure evaluation, titrates sedation intra-procedure, manages airway and hemodynamics, and provides immediate post-procedure recovery. The procedure is performed with the patient in a supine or lateral position (not prone or flat), and the anesthesiologist does not perform the injection itself. Typical workflow: pre-op assessment in procedure suite, IV placement, sedation onset, continuous monitoring (ECG, pulse oximetry, blood pressure), communication with the proceduralist during needle placement and contrast/therapeutic injection, management of sedation-related events if they arise, transfer to PACU for recovery and discharge instructions. Payors commonly involved include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
23 | Unusual anesthesia | Use when anesthesia services are provided for therapeutic procedures that would not ordinarily require anesthesia but are complex or unusually painful. |