No office rate
61598 identifies a transpetrosal route through the petrous temporal bone; 61595 is used for a transtemporal approach.
On this page
CMS RVU26D · Effective 2026-10-01
61598 Skull base approach Medicare reimbursement rates in Missouri
Reports transpetrosal surgical exposure of the skull base to reach lesions near the petrous temporal bone, petroclival region, or brainstem. Compare 61598 office and facility rates across CMS payment localities in Missouri.
Amounts below use the non-QP conversion factor for participating physicians. These are base physician payments before claim-level adjustments, not patient costs or total hospital charges.
What does Medicare pay for 61598 in Missouri?
Missouri has 3 payment localities in this comparison. Use the service location to choose the applicable amount. These are the supported base rates for the 3 payment areas shown below, using the same CMS release.
Office / nonfacility
No supported rate
Facility setting
$2675.22–$2793.29
3 of 3 localities have a supported rate.
These are locality ranges, not averages or address-specific quotes. A facility-setting amount covers the physician service; it does not include a hospital’s separate bill. Choose a locality below to inspect its calculation, compare other payment areas, or price a percentage of Medicare.
Where 61598 pays more and less in Missouri
Skull base surgery
About 61598: Transpetrosal skull base exposure
Reports transpetrosal surgical exposure of the skull base to reach lesions near the petrous temporal bone, petroclival region, or brainstem.
A transpetrosal approach creates access to the skull base through the petrous portion of the temporal bone. Neurosurgeons and otologic or neurotologic surgeons may use this corridor for selected lesions near the petrous bone, petroclival region, or brainstem. The operation is typically performed in a hospital operating room as part of complex skull base surgery; the operative report should identify the route and the exposure performed.
Report this code when the documented skull base exposure uses a transpetrosal corridor, rather than selecting it solely because a lesion is nearby. The record should distinguish the approach from the definitive treatment and describe relevant bone work and the operative target. This major surgery has a 90-day global period, including the day-before preoperative visit and related postoperative care during that period. When multiple procedures are performed in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Modifier 50 is inappropriate for this code. Assistant-at-surgery payment may be available; co-surgeon payment requires supporting documentation, and team surgery is permitted.
CMS billing rules for 61598
- Global period
- Major surgery with a 90-day global period: the day-before preoperative visit and 90 days of related postoperative care are included.
- Multiple procedures
- Standard multiple procedure reduction: the highest-valued procedure is paid in full and others at 50% when performed in the same session.
- Bilateral procedures
- Bilateral adjustment does not apply; the descriptor or anatomy makes modifier 50 inappropriate.
- Assistant at surgery
- Assistant at surgery may be paid.
- Co-surgeons
- Co-surgeons paid only with supporting documentation.
- Team surgery
- Team surgery permitted.
Where the value comes from
- Work RVU35.62 · 42%
- Practice expense (office) RVU34.60 · 41%
- Malpractice RVU15.04 · 18%
48
Medicare services in 2024 · #5382 by national volume
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.
61598 compared with similar codes
Office rates for Missouri, from the same CMS release.
No office rate
Use 61596 when the documented exposure is transcochlear, rather than transpetrosal.
No office rate
61597 represents a transcondylar skull base corridor. The operative route, not simply the lesion's location, separates it from 61598.
Compare 61598 by payment locality
Find the payment area for your service address, then open its rate page for calculation inputs, release history and the percentage-of-Medicare tool. A city may cross payment-area boundaries; the ZIP lookup above helps resolve the location.
3 of 3 payment localities
Metropolitan Kansas City →
Office / nonfacility
Unavailable
Facility
$2765.71
Metropolitan St. Louis →
Office / nonfacility
Unavailable
Facility
$2793.29
Rest Of Missouri →
Office / nonfacility
Unavailable
Facility
$2675.22
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61598 billing questions
How is this approach distinguished from a transtemporal approach?
Choose this code when the operative report identifies a transpetrosal route through the petrous temporal bone. A transtemporal approach is a different skull base corridor.
Should the approach and the definitive operation be reported separately?
The approach code represents the surgical exposure, not the pathology being treated. Review the operative report and applicable coding instructions to determine whether a separately described definitive procedure is also reportable.
Can modifier 50 be used for bilateral work?
No. CMS identifies bilateral adjustment as inapplicable to this code, so modifier 50 is inappropriate.
What documentation supports reporting the transpetrosal approach?
Document the skull base route used, the exposure and bone work performed, and the operative target. The record should make clear why the approach was transpetrosal rather than another skull base corridor.
How does the 90-day global period affect postoperative billing?
The global period includes the day-before preoperative visit and 90 days of related postoperative care. Those services are included in the surgical global period.
Can an assistant or co-surgeon be reported?
Assistant-at-surgery payment may be available. Co-surgeon payment requires supporting documentation; team surgery is permitted.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense, and malpractice RVUs, adjusted by each locality’s geographic indices and the applicable conversion factor. Unavailable or separately priced services are labeled rather than assigned a made-up amount.
Source: RVU26D. Effective 2026-10-01 through the day before 2027-01-01.
6,83161595,,Transtemporal approach/skull,A,,32.90,24.06,NA,24.06,,8.49,65.45,65.45,0,090,0.11,0.76,0.13,2,1,1,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00
6,83261596,,Transcochlear approach/skull,A,,38.44,18.52,NA,18.52,,5.60,62.56,62.56,0,090,0.11,0.76,0.13,2,1,2,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00
6,83361597,,Transcondylar approach/skull,A,,39.80,32.18,NA,32.18,,16.81,88.79,88.79,0,090,0.11,0.76,0.13,2,1,2,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00
6,83461598,,Transpetrosal approach/skull,A,,35.62,34.60,NA,34.60,,15.04,85.26,85.26,0,090,0.11,0.76,0.13,2,0,2,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00
6,83561600,,Resect/excise cranial lesion,A,,29.26,21.58,NA,21.58,,6.49,57.33,57.33,0,090,0.11,0.76,0.13,2,0,2,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00
6,83661601,,Resect/excise cranial lesion,A,,30.36,29.56,NA,29.56,,11.95,71.87,71.87,0,090,0.11,0.76,0.13,2,0,2,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00
6,83761605,,Resect/excise cranial lesion,A,,31.76,19.93,NA,19.93,,5.57,57.26,57.26,0,090,0.11,0.76,0.13,2,0,2,1,2,9,,33.4009,09,0,99,0.00,0.00,0.00