CPT Code 78814: Limited area PET scan billing guide

CPT Code 78814 is the billing code for a positron emission tomography (PET) scan of a limited body area with CT attenuation correction.

The code covers interpretation and a written report. Nuclear medicine and radiology practices bill it for oncologic imaging of one region. A skull base to mid-thigh acquisition is 78815, and vertex-to-feet is 78816.

Medicare coverage runs through National Coverage Determination 220.6.17 and its billing article A58826. Those two documents set the covered indications and require a PI or PS modifier on every oncologic FDG-PET claim.

In a facility setting, the professional component pays roughly $95 to $100 nationally before the geographic adjustment.

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Key takeaways

CPT Code 78814 covers a limited area PET scan with CT attenuation correction and interpretation, distinct from skull-base-to-mid-thigh (78815) and whole body (78816) scans

Medicare pays roughly $95 to $100 for the professional component in 2025, before the geographic adjustment for your MAC jurisdiction

NCD 220.6.17 and billing article A58826 govern oncologic FDG-PET coverage, and NCD 220.6 was retired on January 1, 2022

Coverage splits into two categories: one initial anti-tumor treatment strategy scan (modifier PI) and up to three subsequent strategy scans (modifier PS)

Practice management software like Pabau automates 837P claim submission, verifies eligibility, and flags modifier errors before a claim reaches the payer

What CPT Code 78814 covers

CPT Code 78814 is a nuclear medicine imaging code for a PET scan of a limited body area on a full or partial-ring scanner. The code bundles CT-based attenuation correction, quality control, interpretation, and a written report.

The American Medical Association (AMA), which maintains the CPT code set, lists it among the diagnostic nuclear medicine codes. The CT component serves attenuation correction only, and never bills as a separate diagnostic CT scan.

“Limited area” is the key clinical distinction. It refers to a body region smaller than the skull base-to-mid-thigh range. In practice, this often means imaging focused on a single anatomical region such as the chest, abdomen, or pelvis. A broader scan would not be clinically warranted in those cases.

Medicare reimbursement rates for 78814

Medicare reimbursement for CPT Code 78814 is set annually through the CMS Physician Fee Schedule (PFS). Rates differ between facility and non-facility settings. Every payment is then adjusted by a geographic practice cost index (GPCI) tied to the MAC jurisdiction where the service is rendered.

The arithmetic behind the professional component is worth knowing, because it lets you sanity-check a remittance. Modifier 26 on 78814 carries about 2.95 total RVUs. Multiplied by the 2025 conversion factor of $32.3465, that comes to roughly $95 before any geographic adjustment.

The figures below reflect 2025 national payment rates. Verify them against the current PFS lookup before you submit claims.

Reading the electronic remittance advice after each 78814 claim is paid shows whether the geographic adjustment landed where you expected. Tracking payment variance by MAC jurisdiction across a quarter often surfaces underpayments worth appealing.

Modifiers for CPT Code 78814

Modifier selection for CPT Code 78814 works on two levels. The first is the setting, which decides whether you bill the professional component, the technical component, or both. The second is Medicare’s coverage framework, which requires either PI or PS on every oncologic FDG-PET claim.

Applying the wrong modifier is one of the fastest paths to a denial or a reduced payment on this code family.

Modifier GG does not belong on a PET claim. GG marks the performance and payment of a screening mammography and a diagnostic mammography for the same patient on the same day.

Older PET billing guides pair it with National Oncologic PET Registry (NOPR) requirements, which CMS ended for oncologic FDG-PET when NCD 220.6.17 took effect. The modifiers Medicare requires on this code are PI and PS.

Medicare coverage rules under NCD 220.6.17

Medicare coverage for CPT Code 78814 rests on National Coverage Determination 220.6.17, titled “Positron Emission Tomography (FDG) for Oncologic Conditions.” Its companion billing and coding article is A58826. The NCD sets which oncologic uses Medicare pays for and how many scans it covers.

Article A58826 carries the ICD-10 lists and modifier rules that turn the NCD into a payable claim. That makes it the first reference point for any compliance check on a PET claim. Failing either document produces a non-covered denial, and appeals rarely succeed without new clinical evidence.

Check one thing in your own billing policy first. CMS retired NCD 220.6 on January 1, 2022, so guidance that still cites it for PET points at a withdrawn rule. Article A53134, which often appears next to 220.6 in that guidance, covers PET for non-oncologic conditions such as refractory seizures and suspected dementia. Neither one governs CPT Code 78814.

Initial versus subsequent anti-tumor treatment strategy

NCD 220.6.17 sorts every covered FDG-PET study into one of two categories, and each 78814 claim has to declare which one it belongs to. The category drives the modifier, the number of scans Medicare allows, and the documentation the MAC expects to find in the record.

Initial anti-tumor treatment strategy (modifier PI). This is the scan that informs the first treatment decision for a cancer that is biopsy-proven or strongly suspected on other diagnostic testing. Medicare covers one FDG-PET study per cancer indication here. Most solid tumors qualify, including lung, esophageal, colorectal, head and neck, lymphoma, ovarian, brain, pancreatic, thyroid, testicular, and myeloma.

Four uses are carved out of initial-strategy coverage and are not payable:

• Adenocarcinoma of the prostate
• Breast cancer, for diagnosis and for initial staging of the axillary lymph nodes (staging of distant metastasis remains covered)
• Melanoma, for evaluation of regional lymph nodes
• Cervical cancer, for diagnosis

Subsequent anti-tumor treatment strategy (modifier PS). These are the scans that guide management after the initial course of anti-cancer therapy is finished. Medicare nationally covers three FDG-PET scans per cancer diagnosis in this category. A fourth or later scan is left to MAC discretion and needs modifier KX plus medical necessity documentation in the patient record.

The allowances stack up as shown below, alongside the four indications Medicare carves out of initial-strategy coverage.

Reading the older four-part framework onto a current claim is a common source of denials. Coverage no longer turns on whether a scan is labeled diagnosis, staging, restaging, or treatment response for a named cancer.

It turns on whether the study informs the initial strategy or a subsequent one, and on how many PS scans that diagnosis has already used.

NCD 220.6.17 applies to FDG only. Scans using NaF-18, ammonia N-13, or rubidium-82 sit under separate coverage rules, so confirm the tracer before assuming 220.6.17 governs.

Verifying eligibility before each PET encounter also confirms whether a patient’s Medicare Advantage plan follows the NCD or adds its own restrictions.

Documentation that supports medical necessity

Every 78814 claim submitted to Medicare needs documentation that justifies the scan as medically necessary. The following elements should be in the patient record before the claim is submitted:

• Ordering physician’s notes confirming the oncologic indication and clinical question the PET scan is intended to answer
• Prior conventional imaging reports (CT, MRI, or ultrasound) that were inadequate or inconclusive
• Pathology or biopsy results confirming or strongly suggesting malignancy where applicable
• Treatment history (surgery, chemotherapy, radiation) when billing a subsequent treatment strategy scan with modifier PS
• A running count of prior PS scans for the same cancer diagnosis, so the three-scan limit and any KX claim can be defended
• Signed physician order for the PET scan specifying the clinical indication

Well-run nuclear medicine billing teams organize this documentation before claim submission. Reconstructing it during a denial appeal costs far more time than assembling it up front. A workflow that attaches the clinical documentation to the billing record at the point of service prevents most of that scramble.

CPT 78814 vs 78815 vs 78816: Choosing the right code

The three codes in this PET imaging family are distinguished solely by the body area covered. Selecting the wrong code misrepresents the service and creates a mismatch between the claim and the scan documentation, which payers flag during post-payment audits.

In practice, 78815 is the most frequently billed code because skull-base-to-mid-thigh is the standard scan range for most solid tumor staging and lymphoma workups. CPT Code 78814 applies when the ordering physician has requested imaging of a single body region. The scan report must document that the acquisition was limited to that area.

Billing 78815 when the scan was limited to one region overstates the service. Billing 78814 when a full skull-base-to-mid-thigh acquisition was performed understates it. Both create audit exposure.

ICD-10 codes that support medical necessity

Selecting a diagnosis code that does not appear on the covered ICD-10 list in CMS Article A58826 results in an automatic denial. The table below shows the ICD-10-CM codes most often submitted with CPT Code 78814 for oncologic PET imaging. Each pairing still needs medical necessity documentation in the patient record.

Using Z08 as the primary diagnosis requires that treatment has been completed and the encounter is for follow-up assessment. Submitting Z08 as a primary while treatment is ongoing may trigger a coverage review. Always pair the most specific malignancy code available with any supplementary codes for secondary findings.

HCPCS code A9552: The FDG radiopharmaceutical companion

Every PET scan requires a radiopharmaceutical tracer. For oncologic PET imaging, that tracer is F-18 fluorodeoxyglucose (FDG), billed under HCPCS code A9552.

CPT Code 78814 covers the imaging procedure itself; A9552 covers the radiopharmaceutical supply. Both are billed together on the same claim, but they are distinct line items with separate payment rates.

A9552 is a single-unit code. One unit covers the study dose administered, up to 45 millicuries. The line does not scale with the number of millicuries given. The payment rate is updated annually under the CMS Outpatient Prospective Payment System (OPPS) addendum.

Confirm the administered dose from the physics report, since the code descriptor tops out at 45 millicuries. Leaving A9552 off the claim entirely costs you the tracer supply payment. For practices submitting 837P claims electronically, A9552 goes on a separate service line from 78814.

Common billing errors that trigger denials

Denials on CPT Code 78814 cluster around a small set of predictable errors, and a pre-submission checklist catches most of them. Denial management on high-value nuclear medicine claims starts with knowing which errors recur and where in the workflow they start.

• Non-covered diagnosis: The ICD-10 code submitted does not appear on the covered list in CMS Article A58826. Fix: verify the diagnosis against the article before submitting. Do not rely on the ordering physician’s wording alone.
• Missing PI or PS modifier: The claim carries no treatment-strategy modifier. The MAC cannot tell whether the scan is an initial or a subsequent study under NCD 220.6.17. Fix: assign PI or PS at coding time from the ordering note. Append KX when the scan is the fourth or later PS study for that diagnosis.
• Wrong code in the family: Billing 78814 when the scan acquisition extended to skull-base-to-mid-thigh range, which should be 78815. Fix: compare the scan acquisition range documented in the radiology report against the code description before the claim goes out.
• Missing modifier or wrong modifier: Billing 78814 global at a facility setting without modifier 26, causing a duplicate-billing edit with the facility’s OPPS claim. Fix: confirm place of service before selecting modifier.
• Incomplete medical necessity documentation: The ordering physician’s notes do not document why conventional imaging was inadequate. Fix: build a documentation checklist into the pre-authorization or pre-scan intake workflow.
• A9552 missing or miscoded: The FDG tracer supply line is omitted from the claim, or billed with a unit count above one. Fix: bill one unit per study dose and check the administered dose against the physics report.
• Prior authorization not obtained: Some Medicare Advantage plans require prior authorization for PET imaging. Fix: include prior authorization status in the pre-service eligibility check.

Billing software with built-in edit checks catches most of these errors before the claim reaches the payer. Reviewing the denial codes on returned 78814 claims each quarter shows which errors keep recurring.

It also shows whether the answer is a workflow fix or staff training. Catching an error before submission costs a fraction of what an appeal costs.

How Pabau supports nuclear medicine billing teams

Billing workflows for PET imaging are documentation-heavy and denial-prone. Practice management software like Pabau keeps the clinical record and the claim in one system. The ordering physician’s notes, prior imaging references, and diagnosis codes are captured at the point of encounter.

Your team no longer assembles that evidence by hand before each 78814 claim goes out. Pabau’s claims management software carries the documentation through to submission, so the coder sees the ordering note and the strategy modifier on one screen.

Through Pabau’s integration with Claim.MD, practices submit electronic claims to over 4,000 US payers. Eligibility is verified before the scan date, and ERA remittance is retrieved once claims are adjudicated.

Streamline your nuclear medicine billing workflow

Pabau connects clinical documentation to claims submission and integrates with Claim.MD for electronic 837P filing and ERA retrieval. Modifier errors get flagged before your claims reach the payer. See how it works for nuclear medicine and radiology practices.

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Conclusion

Most 78814 denials come down to a mismatch between the scan that was performed and the claim that describes it. The acquisition range decides the code. The treatment strategy decides the modifier. Neither is a judgment call at coding time, and both are already documented in the chart.

Build the check into the workflow rather than the appeal queue. A biller who confirms the acquisition range, the strategy modifier, and the A58826 diagnosis list before submission will rarely see this code come back. Book a demo to see how Pabau keeps that documentation attached to the claim for nuclear medicine teams.

Continue your research

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Looking for guidance on managing remittance after your claims pay? Electronic remittance advice explained covers how ERA files work and how to reconcile payments against expected reimbursement.

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