CPT code 78831: Tumor SPECT, two or more areas2026 Medicare rate & RVUs in California
Reports radiopharmaceutical tumor imaging with SPECT across two or more areas when tomographic views are used to localize or assess tumor involvement.
Medicare pays $675.06–$873.79 for 78831 in the office in California, from Chico, CA to San Benito County, CA. 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 78831 covers
This service uses a radiopharmaceutical and single-photon emission computed tomography (SPECT) to show tumor-related uptake in two or more areas. Nuclear medicine departments commonly perform the acquisition, and a qualified physician interprets the study for an oncologic workup, such as evaluating suspected tumor distribution or recurrence. The code represents SPECT imaging without the CT component specified by related SPECT/CT codes.
Select this service when the imaging covers at least two areas and includes SPECT; distinguish the count and imaging method from single-area SPECT, SPECT/CT, and planar tumor-localization services. The record should support the clinical reason for imaging, the areas examined, the radiopharmaceutical study performed, and the physician’s interpretation. Report modifier 26 for the professional interpretation or modifier TC for the technical service; reporting without either modifier represents the global service, including both components.
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 78831 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 payment localities
$675.06 to $873.79
29 of 29 payment localities
| Payment locality | Office | Facility |
|---|---|---|
| Bakersfield, CA | $675.57 | Unavailable |
| Chico, CA | $675.06 | Unavailable |
| El Centro, CA | $675.09 | Unavailable |
| Fresno, CA | $675.06 | Unavailable |
| Hanford, CA | $675.06 | Unavailable |
| Los Angeles, CA | $725.75 | Unavailable |
| Madera, CA | $675.06 | Unavailable |
| Marin County, CA | $854.62 | Unavailable |
| Merced, CA | $675.06 | Unavailable |
| Modesto, CA | $675.06 | Unavailable |
| Napa, CA | $801.61 | Unavailable |
| Oxnard, CA | $724.21 | Unavailable |
| Redding, CA | $675.06 | Unavailable |
| Rest of California | $675.06 | Unavailable |
| Riverside, CA | $676.82 | Unavailable |
| Sacramento, CA | $713.60 | Unavailable |
| Salinas, CA | $711.08 | Unavailable |
| San Benito County, CA | $873.79 | Unavailable |
| San Diego, CA | $731.71 | Unavailable |
| San Francisco, CA | $854.44 | Unavailable |
| San Luis Obispo, CA | $699.08 | Unavailable |
| Santa Clara County, CA | $873.05 | Unavailable |
| Santa Cruz, CA | $741.76 | Unavailable |
| Santa Maria, CA | $714.81 | Unavailable |
| Santa Rosa, CA | $749.55 | Unavailable |
| Stockton, CA | $675.06 | Unavailable |
| Vallejo, CA | $801.35 | Unavailable |
| Visalia, CA | $675.06 | Unavailable |
| Yuba City, CA | $675.06 | Unavailable |
How the 78831 rate is calculated
Each of 78831’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 · 78831
RVUs × geographic indexes × conversion factor
Work1.77
1.77 RVUs× 1.000 GPCI
Practice expense16.72
16.72 RVUs× 1.000 GPCI
Malpractice0.16
0.16 RVUs× 1.000 GPCI
Adjusted RVUs
18.6500
Conversion factor
$33.4009
Medicare rate
$622.93
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 78831
The CMS indicators that decide how 78831 is paid alongside other services.
CMS payment indicators · 78831
Tumor SPECT, two or more areas
| Rule | CMS value | What it means |
|---|---|---|
| Global period | XXX | The global surgery concept doesn’t apply. |
| 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) | 0 | Not paid without supporting documentation. |
| Co-surgeons (62) | 0 | Not permitted. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 1 | Diagnostic test with separate professional (26) and technical (TC) components. |
What modifiers do to the payment
Modifier 26 · payment effect
With and without the modifier
78831 without 26 · national office
$622.93
Tumor SPECT, two or more areas
78831-26 · Professional component
$80.83
Pays only the interpretation and report.
78831 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 78803Tumor SPECTSingle body area
- Both use SPECT for tumor localization, but 78803 is for one area; this code is for two or more.
- 78832Tumor SPECT/CTTwo or more areas
- This code describes SPECT across two or more areas without CT. Choose 78832 when the study includes CT.
- 78801Tumor imagingTwo or more areas, one day
- Both cover tumor-localization imaging of two or more areas, but 78801 is planar imaging rather than SPECT.
78831 billing questions
When should this be reported instead of 78803?
Use 78831 when SPECT tumor imaging covers two or more areas. Code 78803 is for SPECT imaging of one area.
How does this differ from 78832?
Both describe tumor-localization SPECT across two or more areas, but 78832 includes CT. This code describes SPECT without that CT component.
Can the professional and technical services be billed separately?
Yes. Modifier 26 identifies the interpretation, and modifier TC identifies the equipment and staff service. Without either modifier, the claim represents the global service.
What documentation supports reporting two or more areas?
Document the clinical indication, the areas imaged, the SPECT study performed, and the interpreting physician’s findings. The record should make clear that the examination covered at least two areas.
Is this the right code for planar imaging of multiple areas?
No. This code is for SPECT. Code 78801 describes planar tumor-localization imaging of two or more areas.
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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