Question: Our surgeon documented that he administered a nerve block to the left side of C3 through C7. How many levels do we consider this when coding? Will we have to apply modifiers for multiple units? Pennsylvania Subscriber Answer: You should base your coding on the facet joint level, rather than the individual nerves, that the surgeon treats. Facet joint nerves C3 and C4 innervate the C3-C4 facet joint. So you would report a nerve block to this joint with 64470 (Injection, anesthetic agent and/or steroid, paravertebral facet joint or facet joint nerve; cervical or thoracic, single level). The C4 and C5 facet joint nerves innervate the C4-C5 facet joint, the C5 and C6 facet joint nerves innervate the C5-C6 facet joint, and the C6 and C7 facet joint nerves innervate the C6-C7 facet joint. Report blocks to each of these facet joints using +64472 (- cervical or thoracic, each additional level [list separately in addition to code for primary procedure]). Your final claim should include 64470 once, plus three units of 64472.