CPT code 20661: Cranial halo, four-pin application2026 Medicare rate & RVUs in Montana

In Montana, Medicare pays $553.34 for 20661 in a facility. There’s no office rate.

Check a contract rate as a % of Medicare · 20661 nationwide

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

What 20661 covers

An orthopedic or neurosurgical provider applies a rigid ring secured to the skull with four pins to support cervical spine immobilization. The halo may be connected to a vest or another support as part of treatment for conditions such as a cervical fracture or instability. This service is generally performed in a hospital or other procedural setting when rigid external stabilization is needed.

Select this code for the four-pin cranial halo application; the six-or-more-pin application is reported with 20664. The application code includes removal of the halo. The record should support the clinical need for rigid stabilization and the pin configuration used. CMS assigns a 90-day global period, including the day-before preoperative visit and 90 days of related postoperative care. When other procedures are performed in the same session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% multiple-procedure reduction. Modifier 50 is inappropriate. Assistant-at-surgery payment is restricted, and co-surgeon and team-surgery billing are not 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.

How Montana compares for 20661

Across 109 of 109 payment localities, the facility rate for 20661 runs from $479.35 in Arkansas to $687.93 in San Benito County, CA. Montana pays $553.34. The RVUs are the same everywhere; the geographic indexes change the dollars.

Every other payment area

20661 rates by state

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

See 20661 in every payment locality

How the 20661 rate is calculated

Each of 20661’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 20661

20661 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 51

Codes related to 20661

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

How 20661 has changed in Montana

Price 20661 for an earlier date of service

Where the Montana rate applies

Montana is a Medicare payment area, not a city. Our Census mapping connects it to 497 cities and communities in Montana. Some span more than one payment area; confirm with the service ZIP.

• Absarokee
• Acton
• Alberton
• Alder
• Alzada
• Amsterdam
• Anaconda-Deer Lodge County
• Antelope

Browse all communities in Montana

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