Billing code 61601: Skull base resectionMedicare rate & RVUs in Washington
Reports removal of an intradural lesion involving the anterior cranial fossa, including dural repair, during complex skull-base surgery.
CMS doesn’t publish an office rate for 61601 in Washington.
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 9 sections
What 61601 covers
Neurosurgeons use this operation to remove a neoplastic, vascular, or infectious lesion involving the anterior cranial fossa from within the dura; dural repair is part of the service. A typical case may involve an olfactory-groove meningioma or another lesion extending into the anterior skull base. The procedure is performed in a hospital operating room and may involve another surgical specialty participating in the approach.
Choose the code based on the lesion’s anterior cranial fossa location and intradural operative work, not simply its diagnosis. The operative report should establish the site, the lesion’s relationship to the dura, the resection performed, and dural repair. This major procedure has a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. When multiple procedures are performed in the same session, the highest-valued is paid in full and other procedures are subject to the standard multiple procedure reduction. Assistant-at-surgery payment may be available; co-surgeon payment requires supporting documentation. 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 61601 pays more and less in Washington
| Payment locality | Office | Facility |
|---|---|---|
| Rest Of Washington | Unavailable | $2,370.64 |
| Seattle (King Cnty) | Unavailable | $2,602.31 |
How the 61601 rate is calculated
Each of 61601’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 · 61601
RVUs × geographic indexes × conversion factor
Work30.36
30.36 RVUs× 1.000 GPCI
Practice expense29.56
29.56 RVUs× 1.000 GPCI
Malpractice11.95
11.95 RVUs× 1.000 GPCI
Adjusted RVUs
71.8700
Conversion factor
$33.4009
Medicare rate
$2,400.52
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 61601
61601 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 61601
Skull base resection
| 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) | 0 | The 150% bilateral adjustment doesn’t apply. |
| 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 · 61601
Skull base resection
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 51 · payment effect
With and without the modifier
61601 without 51 · national facility
$2,400.52
Skull base resection
61601-51 · Second procedure: 50%
$1,200.26
When this isn’t the highest-valued procedure in the session, Medicare pays 50% of its fee schedule amount (the highest is paid at 100%).
61601 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 61600Skull base resection
- Use 61601 for intradural anterior cranial fossa lesion work that includes dural repair; 61600 describes extradural work at that site.
- 61606Skull-base lesion resection
- Both involve intradural lesion resection, but the operative site distinguishes them: anterior cranial fossa for 61601 and middle cranial fossa for 61606.
- 61608Cranial lesion resection
- 61608 is the intradural lesion-resection code for the posterior cranial fossa; 61601 is for the anterior cranial fossa.
61601 billing questions
How is 61601 distinguished from 61600?
61601 is for intradural work involving the anterior cranial fossa and includes dural repair. 61600 describes the corresponding extradural approach.
Does the code include dural repair?
Yes. Dural repair is part of the service represented by 61601, so it is not separately described as an additional repair within this code.
How does 61601 differ from 61606?
Both describe intradural cranial fossa lesion surgery, but 61601 applies to the anterior cranial fossa and 61606 to the middle cranial fossa.
What documentation supports reporting 61601?
Document the anterior cranial fossa site, the lesion’s intradural involvement, the resection performed, and dural repair. The operative report should make the location and extent of the skull-base work clear.
Can an assistant or co-surgeon be reported?
Assistant-at-surgery payment may be available. Co-surgeon payment requires supporting documentation, and 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 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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