CPT code 77321: Radiation plan, special port plan2026 Medicare rate & RVUs

Medicare pays $94.52 for 77321 nationally in the office. Local office rates run $85.00–$124.48.

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

What 77321 covers

A radiation oncologist and the radiation physics team use this planning service to develop a special external-beam treatment arrangement. It is associated with distinctive field designs such as mantle or inverted-Y fields, rather than routine teletherapy isodose plans. The planning work supports the prescribed treatment geometry and dose distribution in radiation oncology settings.

Report 77321 when the documented plan is a special teletherapy port plan, not merely because a conventional plan involves multiple fields or is technically demanding. The record should identify the treatment arrangement and support why this special plan category was used. CMS separately prices the professional and technical components: modifier 26 represents the professional interpretation, and modifier TC represents the technical work, equipment, and staff. Reporting without either modifier represents the global service.

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 77321 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

77321 rates by state

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

How the 77321 rate is calculated

Each of 77321’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 77321

The CMS indicators that decide how 77321 is paid alongside other services.

What modifiers do to the payment

When to use modifier 26

77321 compared with similar codes

How to choose

77306Radiation planSimple teletherapy plan

This code is for a simple teletherapy isodose plan. Choose 77321 when the documented plan is a special port arrangement, such as a mantle or inverted-Y field.

77307Isodose planningComplex teletherapy plan

This code describes a complex teletherapy isodose plan. Complexity alone does not make a plan a special port plan for 77321.

77301IMRT planningDose optimization and volume analysis

This code is for IMRT planning. Use 77321 for a special teletherapy port plan that is not an IMRT plan.

77331Radiation dosimetrySpecial measurement

This code covers special radiation dosimetry, a dosimetry service distinct from developing the special teletherapy port plan reported with 77321.

Codes related to 77321

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