CPT code 61584: Skull base approach2026 Medicare rate & RVUs in Alaska
Reports an extradural orbitocranial route to the anterior cranial fossa using orbital osteotomy, typically to expose lesions at the anterior skull base.
CMS doesn’t publish an office rate for 61584 in Alaska.
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 61584 covers
This code describes an extradural surgical corridor to the anterior cranial fossa created through an orbitocranial approach with orbital osteotomy and elevation of the frontal lobe. Neurosurgeons commonly perform the approach for operations involving anterior skull base lesions, sometimes with an otolaryngologist or craniofacial surgeon participating. It is generally performed in a hospital operating room rather than an office setting.
Select this code when the operative report supports the anterior fossa target, extradural route, and orbital osteotomy; an intradural route is a different service. The 90-day global period includes the day-before preoperative visit and related postoperative care. When multiple procedures occur in one session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. A bilateral procedure 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.
61584 in Alaska*
| Payment locality | Office | Facility |
|---|---|---|
| Alaska* | Unavailable | $3,303.35 |
How the 61584 rate is calculated
Each of 61584’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 · 61584
RVUs × geographic indexes × conversion factor
Work36.76
36.76 RVUs× 1.000 GPCI
Practice expense33.67
33.67 RVUs× 1.000 GPCI
Malpractice14.34
14.34 RVUs× 1.000 GPCI
Adjusted RVUs
84.7700
Conversion factor
$33.4009
Medicare rate
$2,831.39
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 61584
61584 has a 90-day global period: related visits in that window are included in the surgery payment.
CMS payment indicators · 61584
Skull base approach
| 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 · 61584
Skull base approach
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
61584 without 50 · national facility
$2,831.39
Skull base approach
61584-50 · Bilateral: 150%
$4,247.09
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).
61584 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- 61585Orbitocranial approach
- This code describes the extradural orbitocranial route to the anterior cranial fossa. 61585 is the intradural counterpart.
- 61580Craniofacial approach
- 61580 describes a craniofacial route to the anterior cranial fossa. 61584 specifies an orbitocranial route with orbital osteotomy.
- 61592Skull base approach
- Both involve an orbitocranial approach, but 61592 is directed to a different cranial fossa target. Base selection on the operative corridor and target.
61584 billing questions
How does 61584 differ from 61585?
Both describe an orbitocranial approach to the anterior cranial fossa with orbital osteotomy. Choose 61584 for an extradural route and 61585 for an intradural route.
What operative documentation supports 61584?
The operative report should identify the anterior cranial fossa target, the extradural corridor, the orbital osteotomy, and the frontal-lobe elevation performed as part of the approach.
Does the approach code include the lesion resection?
The code describes the surgical approach, not the identity of the lesion or the full extent of its treatment. Review the operative work and applicable CPT instructions when determining whether another procedure code is reportable.
When is modifier 50 appropriate?
Use modifier 50 when the documented service is performed bilaterally. CMS pays a bilateral procedure reported with modifier 50 at 150%.
What postoperative care is included?
The 90-day global period includes the day-before preoperative visit and 90 days of related postoperative care.
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 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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