Summary & Overview
CPT 64421: Intercostal Nerve Injection, Additional Level
CPT code 64421 represents an intercostal nerve injection performed at additional thoracic levels after the first level and is used when providers administer anesthetic and/or steroid adjacent to the ventral branches of the thoracic spinal nerves beneath the ribs. This procedure is clinically relevant for managing thoracic neuropathic pain and post-operative or post-traumatic chest wall pain, and it has implications for utilization, prior authorization, and clinical documentation nationally. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical indication and procedural context for 64421, typical sites of service where the procedure is delivered, and common modifiers used for reporting. The publication also provides benchmark-focused content and policy context relevant to payer coverage and reimbursement practice nationally, as well as coding nuances that affect claim submission and audit risk. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 64421 describes an injection of an anesthetic agent and/or steroid targeted to an intercostal nerve — the ventral branches of thoracic spinal nerves that run beneath each rib. This code is reported for each additional intercostal nerve level treated after the first level.
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Service type: Image-guided or non–image-guided intercostal nerve injection for analgesia or anti-inflammatory effect
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Typical site of service: Outpatient procedure areas such as ambulatory surgical centers, hospital outpatient departments, or physician offices where interventional pain procedures are performed
Clinical & Coding Specifications
Clinical Context
A 54-year-old patient presents to an outpatient ambulatory surgical center with sharp, localized right-sided chest wall pain following recent rib fracture and persistent intercostal neuralgia despite conservative therapy. The pain localizes to the lateral thorax corresponding to the distribution of the right fourth and fifth intercostal nerves. After evaluation by a pain management physician in clinic, the decision is made to perform intercostal nerve injections for diagnostic and therapeutic purposes. The patient is scheduled for the procedure under monitored anesthesia care. In the peri-procedural workflow, informed consent is obtained, allergies and anticoagulation status are reviewed, and pre-procedure imaging (if used) and marking of levels are completed. The provider cleans the skin, uses anatomic landmarks or fluoroscopic/ultrasound guidance to localize the targeted intercostal spaces, and performs an injection of a local anesthetic and corticosteroid adjacent to the intercostal nerve. If multiple contiguous levels require injection, 64421 is reported for each additional level after the first. Post-procedure monitoring is performed in recovery until the patient meets discharge criteria, with instructions for activity and follow-up arranged with the referring clinician.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
25 | Significant, separately identifiable evaluation and management service on the same day |