CPT code 61597: Skull-base approach, transcondylar route2026 Medicare rate & RVUs

Medicare pays $2,965.67 for 61597 nationally in a facility.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

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

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

61597 rates by state

Office rate range in each state. Select a state to see its payment localities.

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.

Payment rules and modifiers for 61597

61597 has a 90-day global period: related visits in that window are included in the surgery payment.

What modifiers do to the payment

When to use modifier 50

61597 compared with similar codes

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.

Codes related to 61597

Related codes aren’t interchangeable: bill the code that matches the service performed.

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

Open CMS sourceHow we calculate rates