CPT code 61597: Skull-base approach, transcondylar route2026 Medicare rate & RVUs in Missouri
Reports a transcondylar route to the posterior cranial fossa, used to reach lesions around the foramen magnum and lower clivus.
CMS doesn’t publish an office rate for 61597 in Missouri.
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 61597 covers
This code represents surgical access to the posterior cranial fossa through a transcondylar route, which provides exposure around the foramen magnum and lower clivus. A neurosurgeon, often working with an otolaryngologist or another skull-base specialist, performs the approach in an operating room. The operative report should identify the route and the exposure performed; the target may be a lesion near the ventral foramen magnum or clivus.
Report the code when the documented operation uses this transcondylar access, rather than a transtemporal, transcochlear, or transpetrosal route. The service has a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. For multiple procedures in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. A bilateral service reported with modifier 50 is paid at 150%. Assistant-at-surgery payment may be available; co-surgeon payment requires supporting documentation, and team surgery is permitted.
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 61597 pays more and less in Missouri
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
| Payment locality | Office | Facility |
|---|---|---|
| Metropolitan Kansas City, MO | Unavailable | $2,887.19 |
| Metropolitan St. Louis, MO | Unavailable | $2,915.20 |
| Rest of Missouri | Unavailable | $2,802.74 |
How the 61597 rate is calculated
Each of 61597’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 · 61597
RVUs × geographic indexes × conversion factor
Work39.80
39.80 RVUs× 1.000 GPCI
Practice expense32.18
32.18 RVUs× 1.000 GPCI
Malpractice16.81
16.81 RVUs× 1.000 GPCI
Adjusted RVUs
88.7900
Conversion factor
$33.4009
Medicare rate
$2,965.67
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 61597
61597 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 61597
Skull-base approach, transcondylar route
| Rule | CMS value | What it means |
|---|---|---|
| Global period | 090 | Major surgery: the day before, the day of, and 90 days after are included. |
| Multiple procedures | 2 | Standard reduction: highest-valued procedure at 100%, others at 50%. |
| Bilateral (modifier 50) | 1 | Bilateral with modifier 50 pays 150% of the fee schedule amount. |
| Assistant at surgery (80/81/82/AS) | 2 | Paid. |
| Co-surgeons (62) | 1 | Permitted with supporting documentation. |
| Team surgery (66) | 2 | Permitted. |
| Professional/technical | 0 | Physician service: no professional/technical split. |
| Split (54/55/56) | 0.11/0.76/0.13 | Share of the payment for pre-op, the procedure itself, and post-op care. |
Global surgery period · 61597
Skull-base approach, transcondylar route
90-day global period ends
Dec 30, 2026
Covers Sep 30, 2026 through Dec 30, 2026 (92 days, including the day before surgery).
Visit on Oct 31, 2026
Day 30 of the 90-day post-op period: related follow-up care is included in the surgical payment.
Pre-op dayGlobal period
What modifiers do to the payment
Modifier 50 · payment effect
With and without the modifier
61597 without 50 · national facility
$2,965.67
Skull-base approach, transcondylar route
61597-50 · Bilateral: 150%
$4,448.51
Both sides on one line with modifier 50 are paid at 150% of the fee schedule amount (subject to multiple-procedure rules with other procedures).
61597 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 61595Skull base approachTranstemporal route
- 61595 identifies a transtemporal approach. Choose 61597 when the operative report documents transcondylar access around the foramen magnum and lower clivus.
- 61596Skull base approachTranscochlear posterior fossa
- 61596 identifies a transcochlear approach; 61597 is for a transcondylar route. The documented surgical pathway distinguishes these codes.
- 61598Skull base approachTranspetrosal corridor
- 61598 identifies a transpetrosal approach. Report 61597 when the access is transcondylar rather than through the petrous region.
61597 billing questions
How is this approach distinguished from a transpetrosal approach?
Use this code when the documented access is transcondylar, around the foramen magnum and lower clivus. A transpetrosal route is a different approach to the posterior cranial fossa.
Does this code describe removal of the lesion?
It identifies the transcondylar surgical access. The operative report should distinguish that access from the definitive treatment of the target; report other services only when separately supported.
What documentation supports reporting this code?
Document the transcondylar route and the exposure performed, including the relevant posterior fossa, foramen magnum, or clival anatomy. The note should make the approach distinguishable from other skull-base routes.
How are multiple procedures in the same session paid?
The highest-valued procedure is paid in full, and other procedures in the session are subject to the standard multiple procedure reduction.
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.
What does the 90-day global period include?
It includes the day-before preoperative visit and 90 days of related postoperative care.
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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