CPT code 20938: Spinal bone graft, structural autograft, separate incision2026 Medicare rate & RVUs in California
Reports structural bone harvested through a separate incision and used to support a spinal fusion, in addition to the primary spine procedure.
CMS doesn’t publish an office rate for 20938 in California.
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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What 20938 covers
During spinal fusion, the surgeon places a structural piece of the patient’s own bone to support the fusion. The graft is harvested through a separate skin or fascial incision; an iliac crest bone block is a typical example. Orthopedic spine surgeons and neurosurgeons may use this service during cervical or lumbar fusion when structural support is needed. The graft is distinct from small local bone fragments collected through the operative exposure and from bone prepared as morselized graft.
Report 20938 only with an eligible primary spinal procedure, not as a stand-alone service. Documentation should identify the separate harvest incision, the autologous graft’s structural use, and the spinal procedure it supports. CMS treats payment for this add-on as part of the primary procedure’s global period. The code includes the graft harvest, so do not separately report another graft-harvest service for the same bone.
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 20938 pays more and less in California
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
29 of 29 payment localities
| Payment locality | Office | Facility |
|---|---|---|
| Bakersfield, CA | Unavailable | $155.83 |
| Chico, CA | Unavailable | $153.30 |
| El Centro, CA | Unavailable | $153.46 |
| Fresno, CA | Unavailable | $153.30 |
| Hanford, CA | Unavailable | $153.30 |
| Los Angeles, CA | Unavailable | $162.63 |
| Madera, CA | Unavailable | $153.30 |
| Marin County, CA | Unavailable | $168.87 |
| Merced, CA | Unavailable | $153.30 |
| Modesto, CA | Unavailable | $153.30 |
| Napa, CA | Unavailable | $164.26 |
| Oxnard, CA | Unavailable | $160.01 |
| Redding, CA | Unavailable | $153.30 |
| Rest of California | Unavailable | $153.30 |
| Riverside, CA | Unavailable | $163.56 |
| Sacramento, CA | Unavailable | $157.38 |
| Salinas, CA | Unavailable | $156.75 |
| San Benito County, CA | Unavailable | $173.87 |
| San Diego, CA | Unavailable | $158.07 |
| San Francisco, CA | Unavailable | $167.78 |
| San Luis Obispo, CA | Unavailable | $154.72 |
| Santa Clara County, CA | Unavailable | $169.41 |
| Santa Cruz, CA | Unavailable | $157.62 |
| Santa Maria, CA | Unavailable | $156.69 |
| Santa Rosa, CA | Unavailable | $158.94 |
| Stockton, CA | Unavailable | $153.30 |
| Vallejo, CA | Unavailable | $162.69 |
| Visalia, CA | Unavailable | $153.30 |
| Yuba City, CA | Unavailable | $153.30 |
How the 20938 rate is calculated
Each of 20938’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 · 20938
RVUs × geographic indexes × conversion factor
Work2.94
2.94 RVUs× 1.000 GPCI
Practice expense0.99
0.99 RVUs× 1.000 GPCI
Malpractice0.96
0.96 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 20938
The CMS indicators that decide how 20938 is paid alongside other services.
CMS payment indicators · 20938
Spinal bone graft, structural autograft, separate incision
| 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) | 1 | Permitted with supporting documentation. |
| 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
20938 without 80 · national facility
$163.33
Spinal bone graft, structural autograft, separate incision
20938-80 · Assistant: 16%
$26.13
A physician assistant at surgery is paid 16% of the surgeon’s fee schedule amount.
20938 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 20937Spinal bone graftMorselized, separate incision
- Both describe autologous bone harvested through a separate incision for spine surgery. Choose 20938 for structural bone and 20937 for morselized bone.
- 20936Spinal autograftLocal, same incision
- Code 20936 covers local bone obtained through the same incision as the spinal procedure; 20938 is for structural autograft harvested through a separate incision.
- 20931Spinal bone graftStructural allograft
- Code 20931 is for structural allograft. Code 20938 is for structural bone harvested from the patient.
20938 billing questions
When should 20938 be chosen instead of 20937?
Use 20938 for a structural autograft harvested through a separate incision. Code 20937 describes autologous bone prepared as morselized graft, rather than a structural bone block.
How does 20938 differ from 20936?
Code 20936 is for local autologous bone obtained through the same incision as the spinal procedure. Code 20938 involves a structural graft harvested through a separate incision.
Can 20938 be reported by itself?
No. It is an add-on code and must be reported with an eligible primary spinal procedure.
Can the harvest be billed separately?
The graft harvest is included in 20938. Document the separate incision and graft use, but do not report another harvest service for that same bone.
What documentation supports 20938?
The operative report should identify the separate harvest incision, the autologous graft’s structural form and use, and the primary spinal procedure.
How does CMS treat the global period?
CMS treats payment for 20938 as occurring within the primary procedure’s global period.
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
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