CPT code 22634: Lumbar fusion, each additional interspace2026 Medicare rate & RVUs in Missouri
Reports each additional lumbar interspace fused using combined posterior or posterolateral and posterior interbody techniques during a multilevel fusion.
CMS doesn’t publish an office rate for 22634 in Missouri.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
Your location
On this page 9 sections
What 22634 covers
This code captures each additional lumbar disc space fused after the first when the surgeon combines a posterior or posterolateral fusion with an interbody fusion performed from the back. The surgeon prepares the disc space and performs interbody fusion while also creating a posterior or posterolateral fusion at that level. Laminectomy or discectomy performed to prepare the interspace is part of the service. Spine surgeons typically report it for multilevel lumbar fusion operations in hospital or ambulatory surgical settings.
Report 22634 for each additional interspace treated with the combined technique beyond the initial level represented by 22633. It is an add-on code and must be billed with that primary procedure; it is paid within the primary procedure's global period. The operative report should identify each fused interspace and document both fusion techniques at each additional level. Count interspaces, not vertebrae or implants.
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 22634 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.
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | Unavailable | $425.24 |
| Metropolitan St. Louis, MO | Unavailable | $428.53 |
| Rest of Missouri | Unavailable | $418.27 |
How the 22634 rate is calculated
Each of 22634’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 · 22634
RVUs × geographic indexes × conversion factor
Work7.76
7.76 RVUs× 1.000 GPCI
Practice expense2.61
2.61 RVUs× 1.000 GPCI
Malpractice2.58
2.58 RVUs× 1.000 GPCI
Adjusted RVUs
12.9500
Conversion factor
$33.4009
Medicare rate
$432.54
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 22634
The CMS indicators that decide how 22634 is paid alongside other services.
CMS payment indicators · 22634
Lumbar fusion, each additional interspace
| Rule | CMS value | What it means |
|---|---|---|
| Global period | ZZZ | Add-on code: falls within the primary procedure’s global period. |
| Multiple procedures | 0 | No multiple-procedure reduction. |
| Bilateral (modifier 50) | 0 | The 150% bilateral adjustment doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 2 | Paid. |
| Co-surgeons (62) | 2 | Permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
What modifiers do to the payment
Modifier 80 · payment effect
With and without the modifier
22634 without 80 · national facility
$432.54
Lumbar fusion, each additional interspace
22634-80 · Assistant: 16%
$69.21
A physician assistant at surgery is paid 16% of the surgeon’s fee schedule amount.
22634 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 22633Lumbar fusionCombined techniques, one level
- 22633 represents the initial lumbar interspace treated with the combined technique. Use 22634 for each additional interspace treated that way.
- 22632Lumbar fusionEach additional interspace
- 22632 applies to each additional level of posterior interbody lumbar fusion alone. 22634 is for an additional level where the posterior or posterolateral fusion technique is combined with interbody fusion.
- 22614Spinal fusionEach additional level
- 22614 is an additional-level code for posterior or posterolateral fusion without the combined interbody technique. Use 22634 when the additional lumbar interspace also receives posterior interbody fusion.
- 22630Lumbar fusionSingle lumbar interspace
- 22630 represents the initial level of posterior interbody lumbar fusion without the combined posterior or posterolateral technique; 22634 is an add-on for additional levels using the combined technique.
22634 billing questions
Which primary code must accompany 22634?
Report 22634 with 22633, which represents the initial lumbar interspace treated with the combined posterior or posterolateral and posterior interbody techniques.
How many units should be reported?
Report one unit for each additional lumbar interspace treated with the combined technique beyond the initial level. Count fused interspaces, not vertebrae.
How does 22634 differ from 22632?
22634 represents an additional interspace treated with combined posterior or posterolateral and posterior interbody fusion. 22632 is the additional-level code for posterior interbody fusion without the combined technique.
What operative documentation supports 22634?
Document the specific additional lumbar interspace and the posterior or posterolateral fusion and posterior interbody fusion performed there.
Is interspace preparation separately described by 22634?
The code includes laminectomy or discectomy performed to prepare the interspace for the interbody fusion. Document the work and its purpose in the operative report.
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
Fee sheets · Coming soon
Put 22634 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Join the waitlist