Pain Management Billing Services: Injections, Modifiers and Prior Auth

Pain management billing services have to get three things right on every spinal injection: a code whose descriptor already includes the imaging guidance, correct laterality and level counts, and documentation that meets the Medicare contractor’s LCD before the procedure. Epidurals (62321, 62323), facet injections (64493, 64494, 64495) and radiofrequency ablation (64635, 64636) depend on all three.

Many pain management denials can be caught before the patient is on the table. The rules come from three places: CPT descriptors, CMS’s NCCI and fee schedule indicators, and the local coverage determination (LCD) of the practice’s Medicare Administrative Contractor. This primer covers the codes that matter and where each one breaks.

The codes that matter

Descriptors come from AAPC:

• 62321 and 62323: interlaminar epidural or subarachnoid injection of a diagnostic or therapeutic substance, cervical or thoracic (62321) or lumbar or sacral, caudal (62323), “with imaging guidance (ie, fluoroscopy or CT)” (AAPC Orthopedic Coding Alert, 7 January 2020).
• 64493, 64494, 64495: paravertebral facet joint injection, or injection of the nerves innervating that joint, “with image guidance (fluoroscopy or CT), lumbar or sacral”: single level, second level, and third and any additional level (AAPC Knowledge Center, 31 December 2021).
• 64635 and 64636: destruction by neurolytic agent, paravertebral facet joint nerve(s), with imaging guidance (fluoroscopy or CT), lumbar or sacral: single facet joint, and each additional facet joint (same AAPC article).
• 20552 and 20553: injection(s), single or multiple trigger point(s), one or two muscle(s), or three or more muscle(s) (AAPC Orthopedic Coding Alert, 20 May 2013).

Fluoroscopy is already in the code

The imaging guidance is part of every spinal code above. CMS’s NCCI Policy Manual, Chapter VIII (revision date 1 January 2026), states that 62321 and 62323 describe injections with fluoroscopic or CT guidance, and that imaging guidance such as 77003 or 77012 is included and should not be reported separately. The same chapter says fluoroscopy reported as 76000 is not reported with spinal procedures unless a CPT instruction says it is separately reportable.

A separate fluoroscopy line on an epidural or facet claim is therefore an edit, not extra revenue. Any charge ticket or EHR order set that still drops a separate guidance line for these procedures should be fixed.

Coverage adds a second layer. Novitas’s LCD L34892 for facet joint interventions (revision effective 11 August 2024) states that facet interventions done without CT or fluoroscopic guidance, including under ultrasound guidance, are not considered medically reasonable and necessary. The procedure note has to name the guidance used.

Laterality, levels and modifier 50

AAPC’s facet guidance (31 December 2021) says the facet injection codes are unilateral, that a bilateral injection at one level is reported with the base code and modifier 50, and that CPT instructs coders not to report modifier 50 with the add-on codes 64494 and 64495. It also says to count levels by the joints injected, not the number of nerves.

Medicare’s own rules sit on top. CMS’s RVU26D file (released 26 August 2026) gives 64493, 64494, 64495, 64635 and 64636 a bilateral surgery indicator of 1, meaning the 150 percent bilateral payment adjustment applies. Novitas’s billing article A56670 (revision effective 5 January 2026) says a bilateral procedure at one level is reported as one unit of the primary code with modifier 50, a unilateral procedure must carry RT or LT, and a line without the right laterality modifier will be rejected. The same article requires the KX modifier on every diagnostic facet injection line.

For a bilateral second level, the CPT instruction and the Novitas instruction differ. AAPC’s example reports the add-on code twice with no modifier 50. Novitas’s A56670 tells its providers to report modifier 50 on each line where the intervention was bilateral, add-on lines included. The billing team needs a written rule for each payer; guessing produces either a denial or an underpayment.

LCD limits: check them before scheduling

The Novitas LCDs, which cover Texas and other states in Jurisdictions H and L, illustrate the documentation Medicare expects. Other contractors publish their own versions, so check yours.

Facet interventions, L34892 (revision effective 11 August 2024):

• One or two levels, unilateral or bilateral, are allowed per session per spinal region. Three- or four-level procedures are not medically necessary and are non-covered.
• A confirmatory diagnostic block requires at least 80 percent relief of the index pain from the first.
• No more than four diagnostic and four therapeutic sessions per region per rolling 12 months.
• Initial RFA requires two diagnostic medial branch blocks, each with at least 80 percent relief. No more than two RFA sessions per region per rolling 12 months.

Epidural steroid injections, L36920 (revision effective 9 April 2026):

• A maximum of four sessions per spinal region in a rolling 12 months, and only one region per session.
• Injections must be performed under CT or fluoroscopic guidance with contrast, unless a documented contrast allergy or pregnancy applies.
• A repeat injection requires documented improvement of at least 50 percent in pain or function for at least three months.

The practical effect: 64495 on a Medicare claim under these LCDs describes a non-covered third level, and a fifth epidural session in 12 months will deny. Both can be caught at scheduling if someone is counting.

Prior authorization: hospital outpatient and WISeR

CMS’s prior authorization program for hospital outpatient departments added facet joint interventions for dates of service on and after 1 July 2023. The current code list includes 64493, 64494, 64635 and 64636. In an update dated 5 August 2024, CMS announced it was removing 64492 and 64495 from the list (effective 16 August 2024, per the code list), explaining that under the revised LCDs three- or four-level procedures are non-covered, so a request would always be non-affirmed.

This program applies to hospital outpatient claims. In Texas, traditional Medicare adds a second layer: CMS’s WISeR Model, which runs from 1 January 2026 to 31 December 2031 in six states, with Texas assigned to Novitas Jurisdiction H. Its operational guide (version 7.0, 24 July 2026) lists epidural steroid injections under L36920, including 62321 and 62323 and the transforaminal codes, and covers the office, ASC and hospital outpatient settings. Providers can request prior authorization or accept pre-payment review. Our post on what WISeR means for Texas practices has the detail.

Commercial and Medicare Advantage plans set their own prior authorization rules, and the billing team has to track them payer by payer.

Trigger points: count muscles, not needles

20552 and 20553 are reported once per session, based on the number of muscles injected. AAPC’s 20 May 2013 guidance corrected a practice that billed 20552 twice for four trigger-point sites: the right code was one unit of 20553. The note should name each muscle.

CMS’s NCCI Policy Manual, Chapter IV (revision date 1 January 2026), adds that trigger point codes are not reported for local anesthesia given to perform another procedure.

Questions to ask a pain management billing partner

1. Do you track LCD session limits per region, per patient, before scheduling?
2. What is your written rule for bilateral add-on levels, payer by payer?
3. Who checks for KX, RT and LT before each claim goes out?
4. How do you manage hospital outpatient, WISeR and commercial prior authorizations?

Our pain management coding guide covers the diagnosis side, and quick-references are in the AMS resources library. When injection claims keep coming back on levels, laterality or LCD limits, that is the work our team has handled for practices since 1992 as part of our medical billing services.