CPT 78018Radiology

Thyroid met imaging body

CPT code 78018 covers imaging performed to detect thyroid cancer that has spread (metastasized) to other parts of the body using radioactive tracers. This specialized nuclear medicine scan helps doctors locate cancer cells outside the thyroid gland.

Showing rates for

National Average

Base Medicare rate

$271.06

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

0.86

PE RVU (NF)

7.45

MP RVU

0.07

Total RVU

8.38

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

NCCI bundling edits

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Billing tips

Verify that diagnostic whole-body scan (78018) is billed separately from therapeutic radioiodine administration (79005), as these are distinct services often performed days apart
Impact: Prevents bundling denials that could cost the full $271.06 reimbursement
Document the specific radiopharmaceutical used (I-123 vs I-131) and dosage, as payers may require this for medical necessity determination
Impact: Reduces medical necessity denials which account for approximately 15-20% of nuclear medicine claim rejections
Bill the global service (without modifier) when facility owns equipment and physician provides interpretation; split with 26/TC only when components are actually separated
Impact: Incorrect modifier use can reduce reimbursement by 85-90% if TC modifier applied when global service performed
Ensure timing of scan relative to thyroid hormone withdrawal or TSH stimulation is documented, as this affects medical necessity determination
Impact: Improves first-pass approval rate and prevents delays in payment averaging 30-45 days for appeals
Link to appropriate ICD-10 codes indicating history of thyroid malignancy (C73, Z85.850) and any confirmed metastases rather than screening codes
Impact: Screening codes may trigger denial; proper diagnosis coding maintains the full $271.06 payment
Verify Medicare LCD coverage requirements for frequency limitations (typically 1-2 scans per year depending on clinical scenario)
Impact: Exceeding frequency limits without documentation can result in complete denial of $271.06 payment

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Frequently asked questions

What is the Medicare reimbursement rate for CPT code 78018 in 2025?

The 2025 Medicare national average reimbursement rate for CPT 78018 is $271.06 for both facility and non-facility settings. This rate is based on 8.38 total RVUs multiplied by the 2025 conversion factor of 32.3465.

What is the difference between CPT 78018 and 78020 for thyroid imaging?

CPT 78018 is used for whole-body imaging to detect thyroid cancer metastases throughout the body, while 78020 covers thyroid uptake measurements with or without limited imaging. Code 78018 is specifically for metastatic disease detection in cancer patients, whereas 78020 evaluates thyroid function.

Can CPT 78018 be billed with modifier 26 for professional component only?

Yes, modifier 26 can be appended to 78018 when billing only the physician's interpretation service separately from the technical component. This is appropriate when the physician reads the study but does not own the equipment or employ the technical staff performing the scan.

How often can CPT 78018 be billed for thyroid cancer surveillance?

Medicare and most commercial payers typically allow 78018 once or twice yearly for thyroid cancer surveillance, depending on risk stratification and clinical guidelines. More frequent imaging requires strong documentation of clinical necessity such as rising tumor markers or new symptoms.

What diagnosis codes support medical necessity for CPT 78018?

Primary supporting codes include C73 (malignant neoplasm of thyroid gland) for active disease, Z85.850 (personal history of malignant neoplasm of thyroid), and specific metastasis codes (C77-C79 series) when metastatic disease is known. Avoid screening codes as these typically result in denial.

Is CPT 78018 bundled with radioiodine therapy administration codes?

No, CPT 78018 (diagnostic imaging) is separate from radioiodine therapy codes like 79005 (therapeutic radioiodine administration). These are distinct services usually performed on different dates - diagnostic scanning typically occurs before therapy or during surveillance, while therapy is a treatment intervention.

What are the work RVUs for CPT code 78018 in 2025?

CPT 78018 has 0.86 work RVUs, 7.45 practice expense RVUs (both facility and non-facility), and 0.07 malpractice RVUs, totaling 8.38 RVUs in 2025 according to the CMS Physician Fee Schedule.