CPT code 33956: ECMO cannula insertion, central, younger than five2026 Medicare rate & RVUs

Medicare pays $756.20 for 33956 nationally in a facility.

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

What 33956 covers

This service covers placing cannulae in central vessels or the heart to establish access for extracorporeal membrane oxygenation or extracorporeal life support in a patient younger than five. It is typically performed by a cardiac surgeon or another surgeon experienced in ECMO cannulation, often in an operating room or intensive care setting when severe cardiac or respiratory failure requires extracorporeal support. The code represents cannula insertion, not the separate work of initiating or managing ECMO/ECLS.

Select the code based on the patient’s age and central rather than peripheral cannula placement. The operative or procedure note should identify the central access site, cannulae placed, and the patient’s age. CMS assigns a 0-day global period, so same-day preoperative and postoperative care is included. When multiple procedures are performed in one session, the highest-valued procedure is paid in full and other procedures are subject to the standard 50% reduction. Modifier 50 is inappropriate. Assistant-at-surgery payment requires medical-necessity documentation; co-surgeon and team-surgery payment require supporting documentation.

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 33956 pays more and less

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

109 of 109 payment localities

33956 rates by state

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

How the 33956 rate is calculated

Each of 33956’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 33956

The CMS indicators that decide how 33956 is paid alongside other services.

What modifiers do to the payment

When to use modifier 51

33956 compared with similar codes

How to choose

33955Central cannulationBirth through age five

Use 33956 for central cannula insertion in a patient younger than five; use 33955 for a patient age five or older.

33952ECMO cannulationPeripheral, percutaneous, younger than five

33952 describes peripheral percutaneous cannula insertion in a younger patient. This code is for central cannula insertion.

33954ECMO cannulationPercutaneous, age 6 and older

33954 describes peripheral open cannula insertion in a younger patient. Choose this code when the cannulae are placed centrally.

33946ECMO initiationVenovenous, age six and older

33946 reports initiation of venovenous ECMO/ECLS; this code reports placement of central cannulae in a younger patient.

Codes related to 33956

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