CPT® Code 64421

Add-On Code

Injection(s), anesthetic agent(s) and/or steroid; intercostal nerve, each additional level (List separately in addition to code for primary procedure)

The procedure described by CPT® Code 64421 involves the injection of anesthetic agents and/or steroids into the intercostal nerves, which are critical for providing sensation and motor function to the upper body, including the thorax and abdominal wall. This type of injection, commonly known as a nerve block, can serve both diagnostic and therapeutic purposes. The intercostal nerves are classified as mixed nerves, meaning they carry both sensory and motor fibers. They emerge from the spinal cord and exit through the intervertebral foramen, subsequently running along the ribs in the intercostal grooves. These nerves are typically accessed for injection at specific anatomical landmarks, such as the posterior axillary line or near the paraspinal muscles at the rib angle. During the procedure, the healthcare provider identifies and marks the injection site along the inferior border of the rib, ensuring precise placement. A needle is then carefully introduced beneath the rib's inferior border and advanced to the subcostal groove, where the anesthetic or steroid is administered. It is important to note that CPT® Code 64421 is used for each additional intercostal nerve level injected, following the primary procedure code, which is CPT® Code 64420 for a single intercostal nerve injection.