CPT code 64642: Chemodenervation, one extremity, 1–4 muscles2026 Medicare rate & RVUs in Missouri
Reports botulinum toxin chemodenervation of one extremity when treatment targets one to four muscles, commonly for focal spasticity or dystonia.
Medicare pays $149.67–$158.72 for 64642 in the office in Missouri, from Rest of Missouri to Metropolitan St. Louis, MO. Which amount applies depends on the service address.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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On this page 9 sections
What 64642 covers
A clinician injects a chemodenervating agent, commonly botulinum toxin, into one to four muscles in a single arm or leg. Neurologists and physical medicine and rehabilitation physicians commonly perform this treatment for focal spasticity, such as after stroke or in cerebral palsy, and for focal dystonia. Services may occur in an office or outpatient hospital. The code represents the treated extremity and muscle-count range, not the number of injection sites or the amount of drug administered.
Document the treated extremity, each muscle injected, and the condition being treated. For another extremity in the same one-to-four-muscle range, report the additional-extremity code 64643 rather than modifier 50. Medicare assigns a 0-day global period, so same-day preoperative and postoperative care is included. When multiple procedures occur in one session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% multiple-procedure reduction. Medicare does not pay an assistant at surgery for this service; co-surgeon and team-surgery reporting are not permitted.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Where 64642 pays more and less in Missouri
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
3 payment localities
$149.67 to $158.72
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | $157.14 | $94.10 |
| Metropolitan St. Louis, MO | $158.72 | $94.81 |
| Rest of Missouri | $149.67 | $91.80 |
How the 64642 rate is calculated
Each of 64642’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · 64642
RVUs × geographic indexes × conversion factor
Work1.61
1.61 RVUs× 1.000 GPCI
Practice expense2.89
2.89 RVUs× 1.000 GPCI
Malpractice0.39
0.39 RVUs× 1.000 GPCI
Adjusted RVUs
4.8900
Conversion factor
$33.4009
Medicare rate
$163.33
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 64642
The CMS indicators that decide how 64642 is paid alongside other services.
CMS payment indicators · 64642
Chemodenervation, one extremity, 1–4 muscles
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 000 | Same-day global: pre- and post-op care on the day of the procedure is included. |
| Multiple procedures | 2 | Standard reduction: highest-valued procedure at 100%, others at 50%. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 1 | Not paid (statutory restriction). |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
What modifiers do to the payment
Modifier 51 · payment effect
With and without the modifier
64642 without 51 · national office
$163.33
Chemodenervation, one extremity, 1–4 muscles
64642-51 · Second procedure: 50%
$81.67
When this isn’t the highest-valued procedure in the session, Medicare pays 50% of its fee schedule amount (the highest is paid at 100%).
64642 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 64643ChemodenervationAdditional extremity, 1-4 muscles
- 64643 is for each additional extremity treated in the one-to-four-muscle range; 64642 reports the first extremity in that range.
- 64644Muscle chemodenervationOne extremity, five or more muscles
- Choose 64644 when five or more muscles are treated in one extremity. Choose 64642 for one to four muscles in that extremity.
- 64645Muscle chemodenervationAdditional extremity, five-plus muscles
- 64645 reports each additional extremity when five or more muscles are treated there; it is not the additional-extremity code for the one-to-four-muscle range.
- 64646Muscle chemodenervationTrunk, one to five muscles
- 64646 is for chemodenervation of trunk muscles. Code 64642 is for one extremity treated in the one-to-four-muscle range.
64642 billing questions
Is 64642 reported per muscle or per extremity?
It represents one extremity treated in the one-to-four-muscle range. Document the individual muscles treated; do not count each muscle or injection site as a separate unit of 64642.
How should treatment of both arms or both legs be reported?
Report 64642 for one extremity and, when the additional extremity is treated in the same one-to-four-muscle range, report 64643 for that additional extremity. Do not use modifier 50.
When should 64644 be used instead?
Use 64644 when five or more muscles are treated in one extremity. The distinction is the number of muscles treated in that extremity, not the number of injection sites.
Are toxin units or injection sites counted as units of 64642?
No. The code is selected by the number of muscles treated in the extremity. Drug quantity and injection sites are not the basis for counting this procedure code.
What same-day care is included in 64642?
Medicare assigns a 0-day global period, which includes same-day preoperative and postoperative care. Other procedures performed in the same session are subject to the standard multiple-procedure reduction.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file lines behind this rate
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