T11, T12 medial branch facet nerves innervate the T12-L1 Joint
T12, L1 innervate L1-L2 Joint
L1, L2 innervate L2-L3 Joint
L2, L3 innervate L3-L4 Joint
L3, L4 innervate L4-5 Joint
L4, L5 innervate L5-S1 Joint
S1 contributing branch would also be included with L5-S1
The above table I first saw from a Pain Management coding webinar from coding consultant Marvel Hammer RN BS CPC CCS-P ACS-PM CHCO
I believe the table would be beneficial to you if you need to reference which medial branches are corresponding the facet joint levels you are reporting. Since the denervation procedures are reported per Facet joint level then I copied some information that pertains to counting per facet joint level below from AMA CPT Assistant Additionally you have mention pulsed versus non-pulsed radiofrequency ablation. You would want to confirm with the physician that the procedure was a non-pulsed procedure to report 64635 64636. Pulsed radiofrequency on the other had are reported with unlisted CPT code 64999 per AMA CPT Assistant. From reading the note, it appears based on the time and temp that it is non pulsed under the 6463X codes. But if for any reason you believe it is pulsed then this needs to be ruled before billing.
What was performed does not appear to be the full procedure note, but appears L3, L4 were ablated thru Radiofrequency bilaterally. In this case as seen in the table above, the L3 and L4 medial branches would innervate the L4-L5 Facet Joint so you would report
64635 with the 50 modifier.
Below is from AMA CPT Assistant that always corresponds that L3, L4, L5 block represents 2 levels L4-L5 (64493) L5-S1 (64494)
Additionally when 4 separate nerves are blocked L2, L3, L4, L5 this would represent 3 levels L3-L4 (64493) L4-L5 (64495) L5-S1 (64495)
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AMA CPT Assistant 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.
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http://dardipainclinic.com/radiofrequency_rhizotomy.php
I copy and pasted the below from the website that had information regarding the anatomy of the medial branches.
The medial branch gives off two sets of branches to the zygapophyseal joints, named by Bogduk and Long the proximal and distal zygapophyseal joints. The proximal zygapophyseal nerve supplies the rostral aspect of the next lower joint. Thus, each zygapophyseal nerve from the medial branch related to it laterally, and the distal zygapophyseal nerve from the next rostral segment. This fact has important implications for facet nerve block and denervation procedures, as both branches need to be blocked or lesioned to completely denervate a single joint.
The course of the medial branch of the dorsal ramus is fixed anatomically at two points: at its origin near the superior aspect of the base of the transverse process, and distally where it emerges from the canal formed by the mammillo-accessory ligament. No reported variations of this anatomy have been found in the literature to date.9
At the L5 level, the transverse process is replaced by the sacral ala, and the L5 dorsal ramus arises from the spinal nerve just outside the L5-S1 intervertebral foramen, passing dorsally over the sacral ala in a groove formed by the junction of the ala with the root of the superior articular process of the sacrum. The medial branch arises as the nerve passes in this groove, and then wraps medially around the posterior aspect of the lumbosacral (L5-S1) zygapophyseal joint, terminating in the multifidus muscle.