CPT code 78122: Blood volume test, whole blood determination2026 Medicare rate & RVUs in Texas
A nuclear medicine blood volume study measures circulating whole blood volume when a clinician needs a direct assessment beyond routine blood counts.
Medicare pays $93.46–$105.91 for 78122 in the office in Texas, from Beaumont, TX to Austin, TX. 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 78122 covers
This study uses a tracer-dilution technique to estimate circulating whole blood volume from patient samples and measurement of the tracer. It is typically performed in a hospital nuclear medicine department, with a nuclear medicine technologist handling the technical procedure and a physician interpreting the results. Clinicians may request it when evaluating suspected abnormalities in circulating blood volume, including certain hematologic disorders.
Report 78122 when the service determines whole blood volume, rather than only plasma volume or red cell mass. The record should support the clinical reason for testing, the tracer and sampling procedure performed, the measurements used, and the physician’s interpretation. CMS recognizes professional and technical components: report modifier 26 for the interpretation, modifier TC for the equipment and staff portion, or neither modifier when billing the global service. CMS separately prices the 26 and TC services.
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 78122 pays more and less in Texas
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
8 payment localities
$93.46 to $105.91
8 of 8 payment localities
| Payment locality | Office | Facility |
|---|---|---|
| Austin, TX | $105.91 | Unavailable |
| Beaumont, TX | $93.46 | Unavailable |
| Brazoria, TX | $100.12 | Unavailable |
| Dallas, TX | $100.71 | Unavailable |
| Fort Worth, TX | $99.90 | Unavailable |
| Galveston, TX | $100.39 | Unavailable |
| Houston, TX | $101.48 | Unavailable |
| Rest of Texas | $96.70 | Unavailable |
How the 78122 rate is calculated
Each of 78122’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 · 78122
RVUs × geographic indexes × conversion factor
Work0.44
0.44 RVUs× 1.000 GPCI
Practice expense2.53
2.53 RVUs× 1.000 GPCI
Malpractice0.06
0.06 RVUs× 1.000 GPCI
Adjusted RVUs
3.0300
Conversion factor
$33.4009
Medicare rate
$101.20
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 78122
The CMS indicators that decide how 78122 is paid alongside other services.
CMS payment indicators · 78122
Blood volume test, whole blood determination
| 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
78122 without 26 · national office
$101.20
Blood volume test, whole blood determination
78122-26 · Professional component
$20.71
Pays only the interpretation and report.
78122 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 78110Plasma volumeSingle sample
- Choose 78110 when the study determines plasma volume alone; 78122 is for determination of whole blood volume.
- 78111Plasma volumeMultiple sampling
- 78111 is the multiple-sample plasma volume service. It does not represent whole blood volume determination.
- 78120Red cell massSingle determination
- 78120 determines red cell mass. Report 78122 when the study determines whole blood volume instead.
78122 billing questions
How is 78122 different from a plasma volume study?
78122 determines whole blood volume. Use a plasma volume code when the measured quantity is plasma volume alone.
How is 78122 different from red cell mass testing?
78122 measures whole blood volume; red cell mass codes concern the circulating red cell component. Select the code that matches the quantity actually determined.
When should modifier 26 or TC be reported?
Use modifier 26 for the physician’s interpretation and report, or TC for the technical service involving equipment and staff. Bill without either modifier for the global service.
What documentation supports 78122?
Document the clinical indication, tracer and sampling procedure, measurements used to determine whole blood volume, and the interpreting physician’s findings.
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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