CPT 77321Radiology

Special teletx port plan

CPT 77321 covers the creation of a specialized treatment plan for radiation therapy that uses custom-designed ports or blocks to protect healthy tissue while targeting cancer cells. This is the planning work that happens before radiation treatment begins.

Showing rates for

National Average

Base Medicare rate

$92.51

This calculator gives a typical-case estimate using standard Medicare modifier rules. Actual payment depends on payer policies, documentation, code-specific CMS status indicators, and locality. Verify before billing.

RVU breakdown

Work RVU

0.95

PE RVU (NF)

1.86

MP RVU

0.05

Total RVU

2.86

Conversion factor: 32.3465 · Source: CMS MPFS RVU25A · Confidence: High

NCCI bundling edits

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Billing tips

Always verify that 77321 is billed only once per treatment course unless significant treatment field modifications occur requiring new port planning
Impact: Prevents automatic denials for duplicate services; improper repeat billing can trigger audits and potential recoupment of $92.51 per instance
Document the specific complexity requiring special port planning versus simple treatment planning codes (77300, 77306-77307)
Impact: Ensures proper code selection and prevents downcoding from 77321 to lower-paying codes; difference can be $40-60 per case
Bundle port film review and verification into 77321; do not separately bill port films performed as part of initial planning
Impact: Avoids unbundling denials and compliance violations; separate billing of included services triggers automated edits
When billing with IMRT or 3D planning codes, ensure 77321 represents distinct simple field planning not included in the complex planning service
Impact: 77321 is typically bundled into IMRT planning (77301, 77385-77386); inappropriate concurrent billing results in $92.51 denial
Verify medical physicist credentials and direct involvement in port planning are documented in medical record
Impact: Audits specifically review qualified personnel involvement; missing credentials documentation can result in full denial and recoupment
Code 77321 applies to external beam therapy planning only; use appropriate brachytherapy codes for internal radiation port planning
Impact: Incorrect code selection for brachytherapy cases results in 100% denial and rebilling delays

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Frequently asked questions

What is the Medicare reimbursement rate for CPT code 77321 in 2025?

The 2025 Medicare national average reimbursement for CPT 77321 is $92.51 for both facility and non-facility settings. This rate is based on 2.86 total RVUs multiplied by the 2025 conversion factor of 32.3465.

How many times can you bill CPT 77321 during a radiation treatment course?

CPT 77321 is typically billed once per treatment course. Additional billing requires clear documentation of medical necessity, such as significant tumor changes, treatment field modifications, or treatment plan revisions that necessitate new port planning. Repeat billing without justification will likely be denied as duplicate services.

What is the difference between CPT 77321 and 77300 for radiation therapy planning?

CPT 77321 is for special teletherapy port planning requiring custom blocking or complex field arrangements, while 77300 represents basic radiation dosimetry calculation and simple treatment planning. Code 77321 involves more complex physics work including custom port design and individualized field shaping, whereas 77300 covers simpler dose calculations.

Can you bill CPT 77321 with IMRT planning codes together?

Generally no. CPT 77321 is typically bundled into comprehensive IMRT planning codes (77301, 77385-77386) and should not be separately billed. IMRT planning includes all treatment planning services. Only bill 77321 separately if it represents distinct simple port planning for a different treatment phase or anatomic area not included in the IMRT plan.

What RVU values are assigned to CPT 77321 in 2025?

For 2025, CPT 77321 has a Work RVU of 0.95, Practice Expense RVU of 1.86 (both facility and non-facility), and Malpractice RVU of 0.05, totaling 2.86 RVUs. These values are from the CMS Medicare Physician Fee Schedule RVU25A released December 23, 2024.

Who can perform and bill for CPT 77321 services?

CPT 77321 must be performed or directly supervised by a qualified radiation oncologist or board-certified medical physicist (ABR, ABMP, or CCPM certified). The service is typically billed by radiation oncology departments, cancer centers, or hospital-based radiation therapy facilities. Proper credentials and qualified personnel involvement must be documented.

What documentation is required to bill CPT 77321 without denials?

Required documentation includes: written treatment plan signed by radiation oncologist, medical physics calculations for custom port design, custom blocking device specifications, port film verification plan, description of structures requiring special shielding, justification for special versus simple planning, qualified medical physicist involvement, and patient diagnosis with treatment intent.