".....refer to the injection of a facet joint either by injection into the joint with one needle puncture or by anesthetizing the two medial branch nerves that supply each joint (two needle punctures). For example, a left-sided L4-L5 intra-articular injection performed with a single needle puncture would be coded as 64475. Injection of the L3 and L4 medial branch nerves supplying the L4-L5 facet joint would also be coded as 64475, even though two separate injections are performed to effect the same result."
Above is from CPT Assistant 2004 and below from 2010
August 2010 page 12
Surgery: Nervous System, 64490, 64491, 64492 (Q&A)
Question: Lumbar medial branch blocks were performed on the right at L3, L4, and L5. Would codes 64490, 64491, and 64492 be reported because three different levels were injected?
Answer: No. The L3, L4, and L5 medial branch nerves innervate the L4-L5 and L5-S1 facet joints. Therefore, code 64493, Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), lumbar or sacral; single level, is reported for the first joint injected or blocked (L4-L5). Code 64493 is reported for a single or initial level treated. Add-on code 64494, Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), lumbar or sacral; second level (List separately in addition to code for primary procedure), is reported for the second joint or level injected or blocked (L5-S1). In this specific instance only, CPT codes 64493 and 64494 should be used, provided the injections were performed in the lumbar spine with fluoroscopic (or CT) guidance, as required to use codes 64490-64495.
To further clarify, add-on code 64495, Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), lumbar or sacral; third and any additional level(s) (List separately in addition to code for primary procedure), is reported only once per day for injections at the third and any additional lumbar or sacral level(s) treated (which does not apply to this case). Codes 64494 and 64495 should only be used in conjunction with code 64493.
CPT codes 64490-64492 are reported in the same way for cervical-thoracic facet injections or blocks. In addition, add-on codes 64492, Injection(s), diagnostic or therapeutic agent, paravertebral facet (zygapophyseal) joint (or nerves innervating that joint) with image guidance (fluoroscopy or CT), cervical or thoracic; third and any additional level(s) (List separately in addition to code for primary procedure) and 64495 are reported once per day as a singular line item irrespective of the number of spinal levels treated.
--------------------------------------------------------------------------------