CPT code 77091: Trabecular bone score, technical calculation only2026 Medicare rate & RVUs in Illinois
Reports the technical computation of a trabecular bone score from DXA data when the calculation is performed separately from data preparation and interpretation.
Medicare pays $24.61–$27.69 for 77091 in the office in Illinois, from Rest of Illinois to Suburban Chicago, IL. 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.
Your location
On this page 9 sections
What 77091 covers
This service calculates a trabecular bone score from DXA image data, generally from a lumbar spine bone-density study. The score analyzes image texture as an indicator of trabecular bone microarchitecture and can contribute to fracture-risk assessment. DXA technologists or other technical staff typically perform the software-based calculation in a bone-density or radiology setting; the calculation does not itself provide a clinician’s interpretation.
Report 77091 for the technical calculation when that work is separately performed. CMS classifies it as a technical-component-only service, with interpretation covered by a separate code; 77092 is used for the interpretation and report. Documentation should identify the DXA data processed and support completion of the calculation. Distinguish this service from 77090, which covers preparation and transmission of data, and from 77089, which describes a TBS service that includes calculation with interpretation and a fracture-risk report.
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 77091 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
4 payment localities
$24.61 to $27.69
| Payment locality | Office | Facility |
|---|---|---|
| Chicago, IL | $27.29 | Unavailable |
| East St. Louis, IL | $24.95 | Unavailable |
| Rest of Illinois | $24.61 | Unavailable |
| Suburban Chicago, IL | $27.69 | Unavailable |
How the 77091 rate is calculated
Each of 77091’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 · 77091
RVUs × geographic indexes × conversion factor
Work0.00
0.00 RVUs× 1.000 GPCI
Practice expense0.79
0.79 RVUs× 1.000 GPCI
Malpractice0.01
0.01 RVUs× 1.000 GPCI
Adjusted RVUs
0.8000
Conversion factor
$33.4009
Medicare rate
$26.72
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 77091
The CMS indicators that decide how 77091 is paid alongside other services.
CMS payment indicators · 77091
Trabecular bone score, technical calculation only
| 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 | 3 | Technical component only. |
77091 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- 77089Trabecular bone scoreComplete service with fracture-risk assessment
- 77089 covers TBS calculation with interpretation and a fracture-risk report. 77091 is for the technical calculation only, with interpretation covered separately.
- 77090TBS processingData preparation and transmission
- 77090 covers preparation and transmission of DXA data for analysis elsewhere; 77091 covers the technical TBS calculation.
- 77092TBS interpretationProfessional component only
- 77092 reports the interpretation and report for TBS. 77091 covers the technical calculation.
- 77080DXA bone density scanAxial skeleton, spine or hip
- 77080 reports axial DXA bone-density measurement. 77091 reports a TBS calculation using DXA data, not the density measurement itself.
77091 billing questions
Does 77091 include the clinician’s interpretation?
No. It covers the technical calculation only; the interpretation and report are covered by a separate code, 77092.
How does 77091 differ from 77090?
77091 represents the technical TBS calculation. 77090 represents preparation and transmission of DXA data for analysis elsewhere.
When would 77089 be considered instead?
77089 describes a TBS service that includes calculation with interpretation and a fracture-risk report. Use the code that reflects the service actually performed and reported.
What documentation supports 77091?
Document the DXA data used and completion of the technical TBS calculation. The interpretation and report belong to the separate interpretation service.
Is this the code for the DXA scan itself?
No. 77091 reports the TBS technical calculation from DXA data, not the bone-density measurement; 77080 is an axial DXA bone-density code.
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
Put 77091 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Build my fee sheet