HCPCS code A9541: Sulfur colloid, per study dose2026 Medicare rate & RVUs in California

CMS doesn’t publish an office rate for A9541 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 A9541 covers

Technetium-99m sulfur colloid is a diagnostic radiopharmaceutical used in nuclear medicine. Depending on the study, it may be administered intravenously for liver-spleen imaging, orally for gastric-emptying evaluation, or by local injection for lymphatic mapping. Nuclear medicine departments and other entities billing the radiopharmaceutical report this code alongside the applicable imaging service when the dose is supplied for the study.

The physician fee schedule status is C: CMS publishes no national payment, and the Medicare Administrative Contractor sets payment for each claim under other contractor pricing. Coverage is left to the contractor’s judgment. One code represents a study dose of up to 20 millicuries; it is not a per-millicurie unit. The dose and administration route depend on the examination being performed.

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 A9541 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 A9541 rate is calculated

Each of A9541’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 A9541

A9541 has no global surgery period, no multiple-procedure, bilateral or assistant-at-surgery adjustment, and no professional/technical split. What changes the payment is where the service happens: the place of service on the claim decides whether Medicare pays the office or the facility rate.

A9541 compared with similar codes

How to choose

A9540Tc-99m MAAPer study dose

A9540 identifies technetium-99m macroaggregated albumin, commonly used for lung perfusion imaging. A9541 identifies sulfur colloid used in different nuclear medicine studies.

A9537MebrofeninPer study dose, up to 15 mCi

A9537 is technetium-99m mebrofenin, used for hepatobiliary imaging. A9541 is sulfur colloid, used for studies such as liver-spleen imaging, gastric emptying, or lymphatic imaging.

A9552FDGPer study dose

A9552 identifies fluorine-18 FDG, a different radiopharmaceutical used in PET imaging. A9541 identifies technetium-99m sulfur colloid for other diagnostic studies.

Codes related to A9541

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