Crystal's MCW Coder Hub🧠 CPT Code 64646 — Chemodenervation of Trunk Muscle(s); 1-5 Muscle(s)
Quick Reference
wRVU: 1.76 | Global Period: 000 (0 days) | Assistant Payable: ❌ No | Bilateral Indicator: 0 | Tiered With: 64647 (6 or more trunk muscles) | Max Units/Session: 1
📋 Clinical Description
CPT 64646 describes the percutaneous injection of a chemical neurolytic agent — most commonly botulinum toxin A or B — into one to five muscles of the trunk to treat spasticity, truncal dystonia, or painful muscle contractions of the axial musculature. Per CPT parenthetical guidelines, the trunk region is strictly defined and includes only the erector spinae, paraspinal muscles, obliques (internal and external), and rectus abdominis. All other muscles — including cervical paraspinals (reported under 64616), iliopsoas (lower extremity), and head/facial muscles — fall outside the trunk coding family and must be reported under their anatomically appropriate codes.
64646 is the lower-tier trunk code and applies when five or fewer distinct trunk muscles are injected in a single session. When six or more trunk muscles require injection, 64647 is the appropriate code and is reported instead of — not in addition to — 64646. These two codes are mutually exclusive for the same session: report one or the other based on the total muscle count, never both. Unlike the extremity chemodenervation family (64642-64645), trunk codes do not use a primary/add-on stacking structure — the trunk is a single anatomic region billed once per session regardless of bilateral paraspinal involvement.
This procedure may be performed in the following clinical contexts:
- Truncal spasticity from spinal cord injury — thoracic and lumbar paraspinal hypertonicity affecting posture, transfer ability, and seating tolerance
- Truncal spasticity from cerebral palsy or TBI — opisthotonos, extensor posturing, or axial tone management in patients with diffuse upper motor neuron involvement
- Axial/truncal dystonia — involuntary sustained contractions of paraspinal or abdominal muscles causing postural deviation; includes camptocormia (anteriorly flexed trunk posture)
- Multiple sclerosis — truncal spasm and axial stiffness contributing to balance, gait, and mobility impairment
- Post-stroke truncal spasticity — less common than limb spasticity but present in patients with significant hemispheric stroke affecting truncal tone
- Abdominal rigidity from neurological conditions — rare indications including tetanus-related muscle spasm or abdominal wall hypertonicity
🔬 Trunk Anatomy — CPT-Defined Scope
Trunk Muscle Definition Is Narrower Than It Appears
CPT defines trunk muscles for the purposes of 64646 and 64647 as only four muscle groups: erector spinae, paraspinal muscles, obliques (internal/external), and rectus abdominis. This is more restrictive than the anatomical definition of trunk musculature. The following muscles are explicitly excluded from 64646 and must be coded elsewhere:
| Muscle | Region per CPT | Correct Code |
|---|---|---|
| Cervical paraspinals (eg, semispinalis cervicis, multifidus cervicis) | Neck | 64616 |
| Sternocleidomastoid | Neck | 64616 |
| Iliopsoas | Lower extremity | 64642 or 64644 |
| Gluteus maximus / medius | Lower extremity | 64642 or 64644 |
| Latissimus dorsi | Variable — confirm with CPT parentheticals; not in the defined trunk list | Query / use most defensible code |
| Pectoralis major / minor | Upper extremity | 64642 or 64644 |
| Masseter / temporalis | Head/face | 64612 or 64615 |
Clinical Pearl — Cervical vs. Thoracic Paraspinals
This is one of the most common misclassification points in trunk chemodenervation billing. Cervical paraspinals are neck muscles and are reported under 64616. Thoracic and lumbar paraspinals are trunk muscles and are reported under 64646 or 64647. When a patient receives injections to both cervical and thoracic/lumbar paraspinals in the same session, both 64616 and 64646 may be billed — they represent distinct anatomic regions. Documentation must clearly identify injection levels (eg, “C5-C6 paraspinals” vs. “T8-T10 paraspinals”) to support separate billing.
✅ Procedure Includes
- Pre-injection assessment of truncal tone, posture, and identification of target trunk muscle(s)
- Needle placement into 1-5 named trunk muscles (erector spinae, paraspinal, obliques, and/or rectus abdominis), percutaneous
- Injection of botulinum toxin or other chemical neurolytic agent into the targeted muscle(s)
- Needle repositioning within the same muscle for multi-site delivery within one muscle (not counted as additional muscles)
- Post-injection monitoring and patient instructions
- Documentation of: all trunk muscles injected by name, total muscle count, injection technique, agent used, dose per muscle, and clinical rationale
✅ Separately Reportable (Not Included)
- 95874 — Needle EMG guidance for chemodenervation injection; list separately in addition to 64646; separately billable when EMG is used to confirm needle placement in the target trunk muscle; do not report 95873 and 95874 together
- 76942 — Ultrasonic guidance for needle placement; list separately when real-time ultrasound guidance is documented; permanent image record required
- 64616 — chemodenervation of neck muscle(s); separately reportable when cervical paraspinals or other neck muscles are injected in the same session alongside trunk muscles; requires distinct documentation of both cervical and trunk injection sites
- 64642 or 64644 — Extremity chemodenervation; separately reportable when extremity and trunk muscles are both injected in the same session; trunk and extremity codes represent distinct anatomic regions and may be reported together with appropriate documentation
- J0585 — OnabotulinumtoxinA (Botox), per unit — bill separately; total units reflect total administered dose across all trunk muscles
- J0586 — AbobotulinumtoxinA (Dysport), per 5 units
- J0587 — RimabotulinumtoxinB (Myobloc), per 100 units
- J0588 — IncobotulinumtoxinA (Xeomin), per unit
Drug Billing — JW and JZ Modifiers
Per CMS billing policy, claims for botulinum toxins dispensed from single-dose vials must report either modifier -JW (drug amount discarded/not administered) or modifier -JZ (no drug discarded) on the J-code line. Failure to append one of these modifiers to drug claims drawn from single-dose containers will result in claim return or rejection. This requirement applies to all Part B drug billing for J0585, J0586, J0587, and J0588.
❌ Excludes / Do Not Report Together
| Code | Description | Relationship to 64646 |
|---|---|---|
| 64647 | Chemodenervation of trunk muscle(s); 6 or more muscle(s) | Mutually exclusive — report 64647 instead of 64646 when 6 or more trunk muscles are injected; do NOT report both in the same session |
| 64616 | Chemodenervation of neck muscle(s), excluding laryngeal muscles | Different anatomic region (cervical muscles); separately reportable when both cervical and trunk injections are performed in the same session with clear documentation of distinct sites |
| 64642 / 64644 | Chemodenervation of one extremity; 1-4 or 5+ muscle(s) | Extremities are a distinct anatomic domain; separately reportable when extremity and trunk injections both occur in the same session |
| 64615 | Chemodenervation; facial, trigeminal, cervical spinal, and accessory nerves | CPT parenthetical guidelines prohibit reporting 64615 alongside 64646 |
64646 and 64647 — Tiered Codes, Not Additive
Unlike the extremity add-on pairs (64643, 64645), 64647 is not stacked on top of 64646. These are tier codes for a single anatomic region — the trunk. When 6 or more trunk muscles are injected, you report 64647 exclusively. When 1-5 trunk muscles are injected, you report 64646 exclusively. Reporting both codes for the same session will generate a bundling edit. There is no scenario in which both 64646 and 64647 are correctly billed for the same patient on the same date of service.
🌳 Code Tree — Destruction by Neurolytic Agent (Trunk Chemodenervation)
CPT 64600-64681 Surgery: Destruction by Neurolytic Agent
│
├── 64612-64617 Chemodenervation — Head, Neck, Larynx
│ ├── 64612 Chemodenervation; facial nerve muscle(s), unilateral
│ ├── 64615 Chemodenervation; facial, trigeminal, cervical spinal, accessory nerves
│ ├── 64616 Chemodenervation; neck muscle(s), excluding laryngeal ← NECK (separately reportable)
│ └── 64617 Chemodenervation; larynx, for spasmodic dysphonia
│
├── 64642 Chemodenervation, 1 extremity; 1-4 muscle(s) ← EXTREMITY (separately reportable)
├── +64643 Chemodenervation, each additional extremity; 1-4 muscle(s)
├── 64644 Chemodenervation, 1 extremity; 5 or more muscle(s) ← EXTREMITY (separately reportable)
├── +64645 Chemodenervation, each additional extremity; 5 or more muscle(s)
│
├── ▶▶ 64646 ◀◀ Chemodenervation, trunk muscle(s); 1-5 muscle(s) ← YOU ARE HERE (Global: 000)
│ └── Trunk muscles: erector spinae, paraspinal (thoracic/lumbar), obliques, rectus abdominis
│ └── Max 1 unit per session | Mutually exclusive with 64647
│
├── 64647 Chemodenervation, trunk muscle(s); 6 or more muscle(s) ← TIERED COUNTERPART
│ └── Report INSTEAD of 64646 when ≥6 trunk muscles injected
│
└── 64650-64653 Eccrine Glands (separate indication)
💰 RVU & Reimbursement Profile
| Component | Value |
|---|---|
| Work RVU (wRVU) | 1.76 (verify against current CMS MPFS for applicable year) |
| Global Period | 000 (0 days) |
| Bilateral Indicator | 0 — trunk is a single body region; not subject to bilateral payment adjustment |
| Max Units Per Session | 1 — only one unit of 64646 per session; use 64647 for 6+ trunk muscles |
| Assistant Surgeon | ❌ Not payable |
| PC/TC Split | ❌ No — procedure code only (Indicator 0) |
| Modifier -51 Exempt | No |
| Anesthesia | Topical or local infiltration; no separate anesthesia billing expected |
Combined Session Billing — Trunk + Extremity + Neck
64646 can be reported in the same session alongside extremity and neck chemodenervation codes when distinct anatomic sites are treated and documentation clearly supports each region. A session that treats thoracic paraspinals (64646), cervical paraspinals (64616), and bilateral lower extremities (64642 + 64643) may report all four codes with appropriate modifiers. The trunk code is not an add-on to any other code — it stands independently alongside other chemodenervation codes for its distinct anatomic region.
🏷️ Modifier Reference
| Modifier | Name | When to Apply |
|---|---|---|
| -25 | Significant, Separately Identifiable E/M | Applied to the E/M code — not 64646 — when a same-day office visit involves evaluation beyond the standard pre-injection assessment; documentation must clearly support distinct MDM |
| -59 | Distinct Procedural Service | When 64646 is billed alongside 64616 or extremity codes and a payer applies inappropriate bundling edits; documents distinct anatomic region and independent service |
| -52 | Reduced Services | Procedure partially completed |
| -53 | Discontinued Procedure | Stopped due to patient safety concern; document reason thoroughly |
| ❌ Not applicable — bilateral paraspinal injections (eg, both sides of the thoracic spine) are reported as a single unit of 64646; the trunk does not have a bilateral modifier equivalent; do not append -50 | ||
| Only applicable when 64646 is billed alongside a separately reportable procedure from a different code family; never needed on 64646 alone |
🩺 Common ICD-10-CM Pairings
Truncal Spasticity — Spinal Cord & Upper Motor Neuron Conditions
| ICD-10 Code | Description | HCC? | HCC Category (v28) | Clinical Notes |
|---|---|---|---|---|
| G82.20 | Paraplegia, unspecified | ✅ Yes | HCC Motor/Cognitive | Thoracic SCI with truncal extensor or flexor spasticity affecting seated posture and transfers |
| G82.50 | Quadriplegia, unspecified | ✅ Yes | HCC Motor/Cognitive | High-level SCI with significant truncal involvement; trunk injections often performed alongside extremity codes |
| G80.0 | Spastic quadriplegic cerebral palsy | ✅ Yes | HCC Motor/Cognitive | Diffuse axial and appendicular spasticity; opisthotonos, extensor posturing |
| G80.3 | Athetoid cerebral palsy | ✅ Yes | HCC Motor/Cognitive | Dyskinetic CP with involuntary trunk movements and axial instability |
| G35.- | Multiple sclerosis | ✅ Yes | HCC Demyelinating | Progressive truncal spasm and axial stiffness; document progressive vs. relapsing-remitting course |
| G81.10 | Spastic hemiplegia, unspecified side | ✅ Yes | HCC Motor/Cognitive | Less common trunk involvement in hemiplegia; document clinical rationale for truncal injection specifically |
| G81.11 | Spastic hemiplegia affecting right dominant side | ✅ Yes | HCC Motor/Cognitive | Right-sided; ipsilateral truncal involvement with unilateral paraspinal hypertonicity |
| I69.351 | Hemiplegia following cerebral infarction, right dominant side | ✅ Yes | Stroke Sequelae HCC | Post-stroke truncal spasticity; preferred over hemiplegia code when stroke etiology is clearly documented |
Truncal / Axial Dystonia
| ICD-10 Code | Description | HCC? | Clinical Notes |
|---|---|---|---|
| G24.1 | Genetic torsion dystonia | ❌ No | Hereditary axial dystonia with trunk involvement; may affect paraspinals, obliques, and core muscles |
| G24.2 | Idiopathic nonfamilial dystonia | ❌ No | Sporadic onset truncal dystonia; no identifiable genetic or secondary cause |
| G24.8 | Other dystonia | ❌ No | Captures camptocormia (severe anteriorly flexed trunk posture from paraspinal dystonia), Pisa syndrome, and other named truncal dystonia variants not classified elsewhere |
Muscle Spasm / Symptom Codes
| ICD-10 Code | Description | HCC? | Clinical Notes |
|---|---|---|---|
| M62.830 | Muscle spasm, unspecified | ❌ No | Per CMS LCD A52848 Group 8, codes M62.411-M62.838 support medical necessity for 64646 when treating spasticity secondary to spastic hemiplegia/hemiparesis |
| M62.838 | Muscle spasm, other site | ❌ No | Use when spasm involves a trunk muscle not more specifically captured elsewhere in the M62.8xx range |
| R25.2 | Cramp and spasm | ❌ No | Lower specificity; use only when a definitive diagnosis has not been established; query provider for underlying etiology when possible |
CMS LCD Coverage — Trunk Chemodenervation
Per CMS Billing and Coding Article A52848, CPT 64646 is covered under Group 8 for treatment of spasticity secondary to spastic hemiplegia and hemiparesis when ICD-10-CM codes M62.411-M62.838 are reported. Coverage for dystonia indications (G24.x) is addressed separately under applicable LCDs. Always verify the current MAC-specific LCD and billing article for your jurisdiction — Noridian (A57185, updated March 2026) and other MACs maintain jurisdiction-specific covered diagnosis lists that may differ from the national article.
🏥 MS-DRG Considerations (Inpatient)
Inpatient Coding Reminder
CPT 64646 is not used in the inpatient facility setting — ICD-10-PCS governs all inpatient procedure coding. The MS-DRGs listed below reflect typical DRG assignments when trunk chemodenervation is performed as part of an inpatient rehabilitation or acute care stay. The principal diagnosis drives DRG assignment; the chemodenervation procedure code itself does not independently trigger a surgical DRG.
Representative DRGs by Principal Diagnosis Category
| MS-DRG | Title | GMLOS | Key Driver |
|---|---|---|---|
| 056 | Degenerative Nervous System Disorders with MCC | ~5.9 days | MS, Parkinson’s, ALS with high-severity comorbidities |
| 057 | Degenerative Nervous System Disorders without MCC | ~3.4 days | MS or Parkinson’s without qualifying secondary diagnoses |
| 052 | Spinal Disorders & Injuries with CC/MCC | ~4.1 days | SCI with significant truncal spasticity; chemodenervation as part of acute or subacute rehab |
| 065 | Intracranial Hemorrhage or Cerebral Infarction with MCC | ~5.0 days | Stroke admission with high-severity comorbidities |
| 559 | Aftercare, Musculoskeletal System & Connective Tissue with MCC | ~4.8 days | Rehabilitation aftercare with MCC secondary diagnoses |
| 560 | Aftercare, Musculoskeletal System & Connective Tissue with CC | ~3.5 days | Rehabilitation aftercare with CC |
CC/MCC Capture in Neurological Inpatients
Patients admitted for conditions driving truncal spasticity frequently have co-documented diagnoses that carry CC/MCC weight. Always code the following when clinically documented and supported by the attending’s record:
🔧 ICD-10-PCS Equivalents (Inpatient Facility Coding)
Note
Inpatient PCS coding for trunk chemodenervation is rare and will not independently drive DRG assignment. The code below is provided for completeness. The same PCS body part character (M = Muscle) applies to both trunk and extremity muscles — PCS does not distinguish trunk vs. extremity at the body part level for this table.
| PCS Code | Full Description | Notes |
|---|---|---|
3E0M3GC | Introduction of Other Therapeutic Substance into Muscle, Percutaneous Approach | Used for botulinum toxin injection into trunk musculature; same code as extremity chemodenervation — body part “M” (Muscle) encompasses all musculature without distinguishing trunk from extremity |
PCS Character Analysis — 3E0M3GC
| Position | Character | Value | Definition |
|---|---|---|---|
| 1 | Section | 3 | Administration |
| 2 | Body System | E | Physiological Systems and Anatomical Regions |
| 3 | Root Operation | 0 | Introduction (putting in or on a therapeutic substance) |
| 4 | Body Part | M | Muscle |
| 5 | Approach | 3 | Percutaneous |
| 6 | Substance | G | Other Therapeutic Substance |
| 7 | Qualifier | C | Other Substance |
PCS Coding Note — Trunk vs. Extremity
Unlike CPT, which distinguishes trunk chemodenervation (64646) from extremity chemodenervation (64642, 64644) through separate codes, ICD-10-PCS uses the same body part character “M” (Muscle) for both regions. When a session involves both trunk and extremity injections, most inpatient facilities assign a single 3E0M3GC code for the encounter rather than multiple lines. Confirm with your facility’s PCS coding policy before assigning multiple lines for the same body part value.
📝 Coding Examples
Example 1 — Office: Thoracic Paraspinal Spasticity, SCI, 4 Trunk Muscles
Clinical Scenario: A 41-year-old male with T6 complete spinal cord injury presents with truncal extensor spasticity interfering with seated balance and wheelchair transfers. The physician injects onabotulinumtoxinA into 4 muscles: right thoracic erector spinae (50u), left thoracic erector spinae (50u), right thoracic multifidus/paraspinal (25u), and left thoracic multifidus/paraspinal (25u). Total dose: 150 units. EMG guidance used. No separately identifiable E/M.
| Field | Code | Rationale |
|---|---|---|
| CPT 1 | 64646 | Chemodenervation, trunk muscle(s); 4 muscles — 1-5 threshold; one unit per session regardless of bilateral paraspinal involvement |
| CPT 2 | 95874 | Needle EMG guidance for chemodenervation; list separately in addition to 64646 |
| Drug | J0585 × 150 | OnabotulinumtoxinA, 150 units total; -JZ modifier if no drug discarded from vial, -JW if some discarded |
| PDx | G82.20 | Paraplegia, unspecified — principal condition driving truncal spasticity |
Note
Even though injections are performed bilaterally (both left and right paraspinals), 64646 is reported as a single unit. The trunk is treated as one anatomic region — bilateral paraspinal injections do not generate two units of 64646, nor does modifier -50 apply. This is a frequent billing error in practices that are accustomed to bilateral extremity code logic.
Example 2 — Office: Truncal Dystonia (Camptocormia), 3 Trunk Muscles
Clinical Scenario: A 67-year-old male with Parkinson’s disease and severe camptocormia (progressive anterior trunk flexion at approximately 70°) presents for paraspinal botulinum toxin injection. The physician documents injection into 3 muscles: bilateral rectus abdominis (treated as 2 muscles, right and left documented separately) and left rectus femoris… wait — no, rectus femoris is NOT a trunk muscle. Corrected scenario: Physician injects bilateral erector spinae (2 muscles) and rectus abdominis (1 muscle). Total: 3 trunk muscles. Ultrasound guidance used. A separately identifiable E/M is documented addressing the patient’s worsening Parkinson’s tremor with medication adjustment.
| Field | Code | Rationale |
|---|---|---|
| CPT 1 | 99214-25 | E/M, established patient, moderate complexity; -25 on E/M — documents separately identifiable management of Parkinson’s tremor distinct from pre-injection assessment |
| CPT 2 | 64646 | Chemodenervation, trunk muscle(s); 3 muscles — 1-5 threshold |
| CPT 3 | 76942 | Ultrasound guidance; list separately; permanent image documentation required |
| Drug | J0585 × [units] | OnabotulinumtoxinA; bill per total units administered as documented |
| PDx | G24.8 | Other dystonia — camptocormia is classified here; document “camptocormia” or “truncal dystonia with anterior flexion” in the attending’s note to support this code selection |
| SDx | G20 | Parkinson’s disease — underlying etiology; supports context for both the E/M and the 64646 injection |
Warning
Modifier -25 belongs on the E/M code only — not on 64646. The documentation must make clear that the Parkinson’s medication evaluation and the pre-injection spasticity assessment are two distinct clinical services occurring in the same visit. Generic documentation (“patient seen for Botox injection and follow-up”) does not satisfy the -25 threshold and will not survive a focused audit.
Example 3 — Office: Combined Trunk and Cervical Paraspinal Injection, Same Session
Clinical Scenario: A 38-year-old female with traumatic brain injury and diffuse spasticity presents for chemodenervation of both the cervical and thoracic/lumbar paraspinal regions. The physician injects: cervical paraspinals bilaterally (C4-C6 level, 2 muscles) and thoracic/lumbar paraspinals bilaterally (T8-L2 level, 4 muscles). EMG guidance is used throughout. No separately identifiable E/M.
| Field | Code | Rationale |
|---|---|---|
| CPT 1 | 64646 | Trunk chemodenervation; 4 muscles (thoracic/lumbar paraspinals) — trunk region per CPT definition |
| CPT 2 | 64616 | Neck chemodenervation; cervical paraspinals — these are neck muscles, not trunk muscles; separately reportable from 64646 as a distinct anatomic region |
| CPT 3 | 95874 | EMG guidance; list separately; one unit when used for the same session across both regions — confirm per-code vs. per-session policy with your MAC |
| Drug | J0585 × [units] | Total onabotulinumtoxinA across all sites; one drug line for total administered units |
| PDx | G81.11 | Spastic hemiplegia affecting right dominant side — underlying etiology driving multi-region spasticity |
Note
This example illustrates the critical anatomical boundary between neck and trunk: cervical paraspinals → 64616; thoracic and lumbar paraspinals → 64646. Both codes are correctly reported together because they represent truly distinct anatomic regions. Modifier -59 on 64646 may be needed with certain payers who attempt to bundle the two codes — documentation must identify the specific spinal levels injected under each code to support separate billing.
⚠️ Common Coding Pitfalls
-
Billing 64646 and 64647 together for the same session: These are mutually exclusive tiered codes. Report 64646 for 1-5 trunk muscles OR 64647 for 6 or more trunk muscles — never both for the same patient on the same date. There is no session in which reporting both is correct.
-
Applying modifier -50 for bilateral paraspinal injections: The trunk is a single body region. Bilateral injection of the paraspinals (eg, both left and right thoracic erectors) is still one unit of 64646. The bilateral indicator for this code is 0 — modifier -50 does not apply and should never be appended.
-
Coding cervical paraspinals under 64646: Per CPT parenthetical guidance, cervical paraspinals are neck muscles and belong under 64616. Reporting them under 64646 is a misclassification. When both cervical and thoracic/lumbar paraspinals are injected, 64616 and 64646 are separately reported with documentation identifying the spinal levels treated.
-
Billing more than one unit of 64646 per session: 64646 has a maximum of 1 unit per date of service. There is no scenario in which multiple units are appropriate — if 6 or more trunk muscles are injected, 64647 is the correct code, not two units of 64646.
-
Misidentifying trunk muscles: Only erector spinae, paraspinals, obliques, and rectus abdominis qualify as trunk muscles under CPT. The iliopsoas, pectoralis, gluteus, and latissimus dorsi are NOT in this defined set. Injecting any of these and coding them as 64646 is a misclassification that will not survive audit.
-
Omitting the drug J-code or missing JW/JZ: The botulinum toxin drug (J0585-J0588) must always be billed separately. Per CMS policy, claims for drugs drawn from single-dose vials must include either modifier -JW (drug discarded) or -JZ (no drug discarded). Missing these modifiers on the J-code line will result in claim return or rejection.
-
Billing 64646 for trigger point injections with botulinum toxin: If the intent of the injection is trigger point treatment rather than chemodenervation of a spastic or dystonic muscle, the correct code may be a trigger point injection code (20552 or 20553), not 64646. The clinical indication — spasticity/dystonia vs. myofascial pain — determines code selection. Botulinum toxin does not automatically make a trigger point injection into 64646.
📎 Sources
AMA CPT 2025 Professional Edition · CMS 2025 Medicare Physician Fee Schedule Final Rule (CMS-1807-F) · CMS RVU25A Relative Value Files · CMS Billing and Coding Article A52848 — Botulinum Toxins · CMS Billing and Coding Article A57185 — Botulinum Toxin Injections (Noridian, updated March 2026) · CMS Billing and Coding Article A57186 — Botulinum Toxin Injections (EMG guidance) · NCCI Policy Manual Chapter 11 (Nervous System), CMS 2024-2025 · ICD-10-CM Official Guidelines for Coding and Reporting FY2025 · ICD-10-PCS Official Guidelines for Coding and Reporting FY2025 · RVU Edge CPT 64646 Profile (2026) · Practical Neurology — Botulinum Toxin Billing & Coding Update (April 2026) · AAPC Knowledge Center — Clinch Chemodenervation Coding (2014, updated principles) · Ambu USA — Myoguide CPT Coding Reference (Trunk Muscle Definition) · Intronix Technologies — EMG Guidance Billing Codes (2025)