CPT code 61591: Skull-base approach, postauricular infratemporal route2026 Medicare rate & RVUs in California

CMS doesn’t publish an office rate for 61591 in California.

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

What 61591 covers

This code represents a postauricular infratemporal route to the middle cranial fossa, generally used when a skull-base lesion requires access through the temporal bone from behind the ear. The operation may include petrous apicectomy and facial nerve mobilization, but the approach does not include resection of the internal auditory canal. Neurosurgeons and otolaryngologists with skull-base expertise may perform it, often in a hospital operating room and sometimes as part of a coordinated surgical team.

Select the code from the operative approach and documented work, not from the diagnosis alone. The report should identify the postauricular route and describe the bone work, facial nerve handling, and whether the internal auditory canal was resected. Medicare assigns a 90-day global period, including the day-before preoperative visit and related postoperative care during that period. When multiple procedures occur in the same session, the highest-valued procedure is paid in full and the others at 50%. Modifier 50 identifies bilateral surgery and 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 61591 pays more and less in California

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

29 of 29 payment localities

How the 61591 rate is calculated

Each of 61591’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 61591

61591 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

61591 compared with similar codes

How to choose

61590Skull base approachInfratemporal, extradural

Both are infratemporal approaches to the middle cranial fossa. Choose 61591 for the postauricular route and 61590 for the preauricular route.

61595Skull base approachTranstemporal route

61595 describes a transtemporal route to the posterior cranial fossa, rather than the postauricular infratemporal route to the middle cranial fossa.

61596Skull base approachTranscochlear posterior fossa

61596 is a transcochlear approach. It is not the postauricular infratemporal approach represented by 61591.

61598Skull base approachTranspetrosal corridor

61598 describes a transpetrosal approach; select between it and 61591 according to the operative corridor documented.

Codes related to 61591

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