CPT code 20931: Spinal bone graft, structural allograft2026 Medicare rate & RVUs in Montana
Report 20931 with spine surgery when a surgeon implants structural donor bone as support, rather than morselized graft material.
In Montana, Medicare pays $98.16 for 20931 in a facility. There’s no office rate.
Check a contract rate as a % of Medicare · 20931 nationwide
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
On this page 11 sections
What 20931 covers
CPT 20931 captures placement of a shaped, donor-derived bone graft that provides structural support during spinal reconstruction or fusion. Unlike chips or granules used to fill a fusion bed, this graft retains a block or strut form and may help maintain spacing or support between vertebrae. A spine surgeon typically places it during an operative spinal fusion, such as an interbody fusion, in a hospital or ambulatory surgical setting. The graft is allograft tissue, not bone harvested from the patient during the operation.
Report 20931 only alongside an eligible primary spine procedure; it is an add-on, not a stand-alone service. The operative report should identify the structural allograft and its role in the spinal reconstruction, distinguishing it from morselized allograft and structural autograft. CMS pays this add-on within the primary procedure’s global period.
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.
How Montana compares for 20931
Across 109 of 109 payment localities, the facility rate for 20931 runs from $83.73 in Wisconsin to $129.14 in Miami, FL. Montana pays $98.16. The RVUs are the same everywhere; the geographic indexes change the dollars.
- Montana · this page$98.16
- Los Angeles, CA · California$97.59−$0.57
- Washington, DC area · District of Columbia$107.11+$8.95
- Miami, FL · Florida$129.14+$30.98
- Chicago, IL · Illinois$124.23+$26.07
- Manhattan, NY · New York$116.70+$18.54
- Alaska · Alaska$120.02+$21.86
Other areas in Montana first, then benchmark localities. Bars start at $0.
Every other payment area
| Payment locality | Office | Facility |
|---|---|---|
| AlabamaAlabama | — | $87.18 |
| ArkansasArkansas | — | $85.86 |
| ArizonaArizona | — | $94.75 |
| Bakersfield, CACalifornia | — | $93.50 |
| Chico, CACalifornia | — | $91.95 |
| El Centro, CACalifornia | — | $92.04 |
| Fresno, CACalifornia | — | $91.95 |
| Hanford, CACalifornia | — | $91.95 |
| Madera, CACalifornia | — | $91.95 |
| Merced, CACalifornia | — | $91.95 |
| Modesto, CACalifornia | — | $91.95 |
| Napa, CACalifornia | — | $98.47 |
| Oxnard, CACalifornia | — | $96.00 |
| Redding, CACalifornia | — | $91.95 |
| Rest of CaliforniaCalifornia | — | $91.95 |
| Riverside, CACalifornia | — | $98.25 |
| Sacramento, CACalifornia | — | $94.38 |
| Salinas, CACalifornia | — | $94.01 |
| San Diego, CACalifornia | — | $94.80 |
| Marin County, CACalifornia | — | $101.20 |
| San Francisco, CACalifornia | — | $100.53 |
| San Benito County, CACalifornia | — | $104.23 |
| Santa Clara County, CACalifornia | — | $101.49 |
| San Luis Obispo, CACalifornia | — | $92.79 |
| Santa Cruz, CACalifornia | — | $94.53 |
| Santa Maria, CACalifornia | — | $93.97 |
| Santa Rosa, CACalifornia | — | $95.31 |
| Stockton, CACalifornia | — | $91.95 |
| Vallejo, CACalifornia | — | $97.51 |
| Visalia, CACalifornia | — | $91.95 |
| Yuba City, CACalifornia | — | $91.95 |
| ColoradoColorado | — | $95.85 |
| ConnecticutConnecticut | — | $105.03 |
| DelawareDelaware | — | $96.27 |
| Fort Lauderdale, FLFlorida | — | $114.38 |
| Rest of FloridaFlorida | — | $107.24 |
| Atlanta, GAGeorgia | — | $102.65 |
| Rest of GeorgiaGeorgia | — | $99.85 |
| Hawaii, Guam, HIHawaii | — | $92.60 |
| IowaIowa | — | $84.64 |
| IdahoIdaho | — | $86.24 |
| East St. Louis, ILIllinois | — | $116.60 |
| Rest of IllinoisIllinois | — | $107.58 |
| Suburban Chicago, ILIllinois | — | $114.36 |
| IndianaIndiana | — | $86.63 |
| KansasKansas | — | $86.53 |
| KentuckyKentucky | — | $94.34 |
| New Orleans, LALouisiana | — | $99.72 |
| Rest of LouisianaLouisiana | — | $95.10 |
| Metropolitan Boston, MAMassachusetts | — | $102.26 |
| Rest of MassachusettsMassachusetts | — | $96.18 |
| Baltimore area, MDMaryland | — | $105.25 |
| Rest of MarylandMaryland | — | $97.41 |
| Rest of MaineMaine | — | $89.17 |
| Southern Maine, MEMaine | — | $90.75 |
| Detroit, MIMichigan | — | $111.03 |
| Rest of MichiganMichigan | — | $99.03 |
| MinnesotaMinnesota | — | $84.90 |
| Metropolitan Kansas City, MOMissouri | — | $96.54 |
| Metropolitan St. Louis, MOMissouri | — | $97.29 |
| Rest of MissouriMissouri | — | $94.97 |
| MississippiMississippi | — | $90.32 |
| North CarolinaNorth Carolina | — | $89.76 |
| North DakotaNorth Dakota | — | $86.49 |
| NebraskaNebraska | — | $84.42 |
| New HampshireNew Hampshire | — | $96.54 |
| Northern New JerseyNew Jersey | — | $106.40 |
| Rest of New JerseyNew Jersey | — | $104.27 |
| New MexicoNew Mexico | — | $100.52 |
| NevadaNevada | — | $94.93 |
| NYC suburbs and Long Island, NYNew York | — | $122.57 |
| Poughkeepsie and northern NYC suburbs, NYNew York | — | $106.85 |
| Queens, NYNew York | — | $114.26 |
| Rest of New YorkNew York | — | $91.36 |
| OhioOhio | — | $96.64 |
| OklahomaOklahoma | — | $91.70 |
| Portland, OROregon | — | $96.28 |
| Rest of OregonOregon | — | $92.27 |
| Metropolitan Philadelphia, PAPennsylvania | — | $103.87 |
| Rest of PennsylvaniaPennsylvania | — | $95.50 |
| Puerto RicoPuerto Rico | — | $98.12 |
| Rhode IslandRhode Island | — | $97.84 |
| South CarolinaSouth Carolina | — | $93.74 |
| South DakotaSouth Dakota | — | $85.11 |
| TennesseeTennessee | — | $87.28 |
| Austin, TXTexas | — | $97.21 |
| Beaumont, TXTexas | — | $95.03 |
| Brazoria, TXTexas | — | $94.16 |
| Dallas, TXTexas | — | $95.85 |
| Fort Worth, TXTexas | — | $95.91 |
| Galveston, TXTexas | — | $95.14 |
| Houston, TXTexas | — | $105.94 |
| Rest of TexasTexas | — | $95.28 |
| UtahUtah | — | $95.01 |
| VirginiaVirginia | — | $92.07 |
| Virgin Islands, VIUnited States Virgin Islands | — | $98.12 |
| VermontVermont | — | $88.27 |
| Rest of WashingtonWashington | — | $95.30 |
| King County, WAWashington | — | $102.01 |
| WisconsinWisconsin | — | $83.73 |
| West VirginiaWest Virginia | — | $104.11 |
| WyomingWyoming | — | $93.07 |
20931 rates by state
Office rate range in each state. Select a state to see its payment localities.
Explore a state
Local rates. Clear comparisons.
Hover or focus a tile to see its rate range. Select it to open the state’s fee schedule.
View every state and territory as a table
| State / territory | Office rate range | Localities |
|---|---|---|
| AK | No published base rate | 1 |
| AL | No published base rate | 1 |
| AR | No published base rate | 1 |
| AZ | No published base rate | 1 |
| CA | No published base rate | 29 |
| CO | No published base rate | 1 |
| CT | No published base rate | 1 |
| DC | No published base rate | 1 |
| DE | No published base rate | 1 |
| FL | No published base rate | 3 |
| GA | No published base rate | 2 |
| GU | No published base rate | 1 |
| HI | No published base rate | 1 |
| IA | No published base rate | 1 |
| ID | No published base rate | 1 |
| IL | No published base rate | 4 |
| IN | No published base rate | 1 |
| KS | No published base rate | 1 |
| KY | No published base rate | 1 |
| LA | No published base rate | 2 |
| MA | No published base rate | 2 |
| MD | No published base rate | 3 |
| ME | No published base rate | 2 |
| MI | No published base rate | 2 |
| MN | No published base rate | 1 |
| MO | No published base rate | 3 |
| MS | No published base rate | 1 |
| MT | No published base rate | 1 |
| NC | No published base rate | 1 |
| ND | No published base rate | 1 |
| NE | No published base rate | 1 |
| NH | No published base rate | 1 |
| NJ | No published base rate | 2 |
| NM | No published base rate | 1 |
| NV | No published base rate | 1 |
| NY | No published base rate | 5 |
| OH | No published base rate | 1 |
| OK | No published base rate | 1 |
| OR | No published base rate | 2 |
| PA | No published base rate | 2 |
| PR | No published base rate | 1 |
| RI | No published base rate | 1 |
| SC | No published base rate | 1 |
| SD | No published base rate | 1 |
| TN | No published base rate | 1 |
| TX | No published base rate | 8 |
| UT | No published base rate | 1 |
| VA | No published base rate | 2 |
| VI | No published base rate | 1 |
| VT | No published base rate | 1 |
| WA | No published base rate | 2 |
| WI | No published base rate | 1 |
| WV | No published base rate | 1 |
| WY | No published base rate | 1 |
How the 20931 rate is calculated
Each of 20931’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 · 20931
RVUs × geographic indexes × conversion factor
Work1.76
1.76 RVUs× 1.000 GPCI
Practice expense0.59
0.59 RVUs× 1.000 GPCI
Malpractice0.59
0.59 RVUs× 1.000 GPCI
Adjusted RVUs
2.9400
Conversion factor
$33.4009
Medicare rate
$98.20
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
The exact Montana inputs and CMS source lines
PPRRVU2026_Oct_nonQPP.csv
1,812
- Code
- 20931
- Physician work
- 1.76
- Practice expense
- 0.59
- Malpractice
- 0.59
GPCI2026.csv
71
- Locality
- Montana
- Physician work
- 1.000
- Practice expense
- 1.000
- Malpractice
- 0.998
| Component | RVU | Locality factor | Adjusted |
|---|---|---|---|
| Physician work | 1.76 | × 1.000 | 1.7600 |
| Practice expense | 0.59 | × 1.000 | 0.5900 |
| Malpractice | 0.59 | × 0.998 | 0.5888 |
| Total RVUs | 2.9388 | ||
| Conversion factor | × 33.4009 | ||
Facility rate, Montana$98.16
Facility: (1.76 × 1 + 0.59 × 1 + 0.59 × 0.998) × $33.4009 = $98.16
Payment rules and modifiers for 20931
The CMS indicators that decide how 20931 is paid alongside other services.
CMS payment indicators · 20931
Spinal bone graft, structural allograft
| 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) | 1 | Not paid (statutory restriction). |
| Co-surgeons (62) | 1 | Permitted with supporting documentation. |
| Team surgery (66) | 0 | Not permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
How 20931 has changed in Montana
20931 · Office / nonfacility
Rate unavailable
Effective 2026-10-01
A rate is unavailable in one of these releases, so a change cannot be calculated.
One bar per available release, ordered by effective date. Missing rates remain gaps. These comparisons hold the code, setting and locality identifiers constant; they do not isolate which policy or input caused a change.
What changed, release by release
| Effective from | Office | Facility | CMS release |
|---|---|---|---|
| 2026-10-01 | Not available in this setting | $98.16 | RVU26D |
| 2026-07-01 | Not available in this setting | $98.16 | RVU26C |
| 2026-04-01 | Not available in this setting | $98.16 | RVU26B |
| 2026-01-01 | Not available in this setting | $98.16 | RVU26A |
| 2025-10-01 | Not available in this setting | $107.29 | RVU25D |
| 2025-07-01 | Not available in this setting | $107.29 | RVU25C |
| 2025-04-01 | Not available in this setting | $107.29 | RVU25B |
| 2025-01-01 | Not available in this setting | $107.29 | RVU25A |
| 2024-10-01 | Not available in this setting | $109.42 | RVU24D |
| 2024-07-01 | Not available in this setting | $109.42 | RVU24C |
| 2024-04-01 | Not available in this setting | $109.42 | RVU24B |
| 2024-03-09 | Not available in this setting | $109.42 | RVU24AR |
| 2024-01-01 | Not available in this setting | $107.63 | RVU24A |
| 2023-10-01 | Not available in this setting | $111.06 | RVU23D |
| 2023-07-01 | Not available in this setting | $111.06 | RVU23C |
| 2023-04-01 | Not available in this setting | $111.06 | RVU23B |
| 2023-01-01 | Not available in this setting | $111.06 | RVU23A |
| 2022-10-01 | Not available in this setting | $112.37 | RVU22D |
| 2022-07-01 | Not available in this setting | $112.37 | RVU22C |
| 2022-04-01 | Not available in this setting | $112.37 | RVU22B |
| 2022-01-01 | Not available in this setting | $112.37 | RVU22A |
| 2021-10-01 | Not available in this setting | $112.97 | RVU21D |
| 2021-07-01 | Not available in this setting | $112.97 | RVU21C |
| 2021-04-01 | Not available in this setting | $112.97 | RVU21B |
| 2021-01-01 | Not available in this setting | $112.97 | RVU21A |
| 2020-10-01 | Not available in this setting | $122.13 | RVU20D |
| 2020-07-01 | Not available in this setting | $122.13 | RVU20C |
| 2020-04-01 | Not available in this setting | $122.13 | RVU20B |
| 2020-01-01 | Not available in this setting | $122.13 | RVU20A |
| 2019-10-01 | Not available in this setting | $131.13 | RVU19D |
| 2019-07-01 | Not available in this setting | $131.13 | RVU19C |
| 2019-04-01 | Not available in this setting | $131.13 | RVU19B |
| 2019-01-01 | Not available in this setting | $131.13 | RVU19A |
| 2018-10-01 | Not available in this setting | $131.35 | RVU18D |
| 2018-07-01 | Not available in this setting | $131.35 | RVU18C |
| 2018-04-01 | Not available in this setting | $131.35 | RVU18B |
| 2018-01-01 | Not available in this setting | $131.35 | RVU18AR1 |
| 2017-10-01 | Not available in this setting | $127.47 | RVU17D |
| 2017-07-01 | Not available in this setting | $127.47 | RVU17C |
| 2017-04-01 | Not available in this setting | $127.47 | RVU17B |
| 2017-01-01 | Not available in this setting | $127.47 | RVU17A |
| 2016-10-01 | Not available in this setting | $122.73 | RVU16D |
| 2016-07-01 | Not available in this setting | $122.73 | RVU16C |
| 2016-04-01 | Not available in this setting | $122.73 | RVU16B |
| 2016-01-01 | Not available in this setting | $122.73 | RVU16A |
| 2015-10-01 | Not available in this setting | $124.06 | RVU15D |
| 2015-07-01 | Not available in this setting | $124.06 | RVU15C |
| 2015-04-01 | Not available in this setting | $123.44 | RVU15B |
| 2015-01-01 | Not available in this setting | $123.44 | RVU15A |
| 2014-10-01 | Not available in this setting | $118.90 | RVU14D |
| 2014-07-01 | Not available in this setting | $118.90 | RVU14C |
| 2014-04-01 | Not available in this setting | $118.90 | RVU14B |
| 2014-01-01 | Not available in this setting | $118.90 | RVU14A |
| 2013-10-01 | Not available in this setting | $114.24 | RVU13D |
| 2013-07-01 | Not available in this setting | $114.24 | RVU13C |
| 2013-04-01 | Not available in this setting | $114.24 | RVU13B |
| 2013-01-01 | Not available in this setting | $114.24 | RVU13AR |
Where the Montana rate applies
Montana is a Medicare payment area, not a city. Our Census mapping connects it to 497 cities and communities in Montana. Some span more than one payment area; confirm with the service ZIP.
- Absarokee
- Acton
- Alberton
- Alder
- Alzada
- Amsterdam
- Anaconda-Deer Lodge County
- Antelope
20931 billing questions
Can 20931 be reported without a primary spine procedure?
No. It is an add-on code and must be reported with a primary procedure.
How does 20931 differ from 20930?
20931 represents structural donor bone used as a supporting graft. Code 20930 is for morselized donor bone, such as chips or granules used to fill a fusion bed.
How does 20931 differ from 20938?
Both describe structural grafting for spine surgery, but 20931 is for donor bone and 20938 is for bone graft taken from the patient.
What documentation supports reporting 20931?
The operative report should identify the donor-derived graft as structural and describe its placement and role in the spinal reconstruction.
How does CMS treat payment for 20931?
CMS treats it as an add-on paid 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
Show the CMS file lines behind this rate
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