CPT Code 78452: Nuclear Stress Test Coding, 78451 vs 78452 and Billing With 93015

A nuclear stress test usually ends up as four or five lines on a claim: the imaging, the stress test, the stress drug and the radiotracer, each with its own code and its own units. Denials on these claims often come from a few predictable mismatches: 78451 billed for a rest and stress study, 93015 billed by a physician who only read the ECG, or a pharmacologic test with no note explaining why the patient could not exercise.

This guide explains what the 78452 CPT code covers, how it differs from 78451, how it pairs with 93015 and the stress test component codes, how Lexiscan and tracer units work, and what Medicare and other payers check before they pay. Three tools help you pick the imaging code, assemble the claim lines for your setting, and run a final check before submission.

Quick answer: CPT code 78452 reports SPECT myocardial perfusion imaging with multiple studies, usually rest and stress images, whether they are taken on one day or two. It covers the imaging and its interpretation only. The stress test (93015 to 93018), the stress drug and the radiotracer are reported with their own codes when they are separately billable.

What Is CPT Code 78452?

CPT 78452 reports myocardial perfusion imaging (MPI) performed with single-photon emission computed tomography (SPECT) when more than one study is acquired. In plain terms, it is the imaging half of a nuclear stress test. A radiotracer is injected, and the gamma camera records how it spreads through the heart muscle, so the reader can compare blood flow at rest with blood flow under stress.

The CPT descriptor, which is copyrighted by the American Medical Association and paraphrased here, defines “multiple studies” as any combination of rest imaging, stress imaging (exercise or pharmacologic), redistribution imaging and rest reinjection imaging. It also folds several processing steps into the code when they are performed:

• Attenuation correction.
• Qualitative or quantitative wall motion assessment.
• Ejection fraction, by first-pass or gated technique.
• Additional quantification. The Medicare NCCI manual adds that this includes any heart-lung ratio, which is not billed separately with a lung perfusion code.

So the gated ejection fraction and wall motion reported on a SPECT study are not extra charges. The same included services apply to 78451, the single-study code. What 78452 does not include is the cardiovascular stress test, the stress drug or the radiopharmaceutical; those are covered in the sections below. If you code across the whole specialty, our cardiology CPT codes guide places these codes alongside ECG, echo and catheterization codes.

Is CPT 78452 a Radiology Code?

Yes. 78452 sits in the nuclear medicine subsection of the CPT Radiology section (codes 70010 to 79999), and the Medicare NCCI policy manual covers it in its radiology chapter. That placement is about where the code lives in the code set, not who may bill it. Cardiologists report 78452 routinely. What matters for payment is that the reading physician meets the payer’s credentialing and accreditation requirements, and that commercial plans often route nuclear cardiology through their radiology or advanced imaging authorization programs.

What Is the Difference Between CPT Code 78451 and 78452?

The difference is the number of SPECT perfusion studies. The 78451 CPT code description covers one study, taken either at rest or under stress (exercise or pharmacologic), with the same included processing as 78452. 78452 covers two or more studies. The number of images, camera positions or reconstructions does not matter; the number of distinct studies in the protocol does.

Feature	CPT 78451	CPT 78452
Studies	One SPECT perfusion study	Two or more SPECT perfusion studies
Typical protocols	Stress only (rest images not needed); rest only	Rest and stress; stress and redistribution; rest, stress and rest reinjection
Tracer doses	Usually one	Usually two for technetium rest and stress protocols
Two-day protocol	Not used to split a rest and stress study	Reported once, covering both days
Included when performed	Attenuation correction, wall motion, ejection fraction, additional quantification	Same

Three situations cause most of the coding errors:

• Two-day protocols. When rest images are taken one day and stress images another, the service is still one multiple-study examination. Report 78452 once, not 78451 twice (this follows from the CPT descriptor’s “multiple studies” wording; see MedLearn Publishing’s cardiology coding question of the week). Some payers specify which date of service to use for a two-day study, so check the payer’s instruction.
• Stress-first protocols. When the stress images are normal and the rest study is never performed, only one study exists. That is 78451, even though the order said “rest and stress.”
• Planar or PET imaging. 78451 and 78452 are SPECT codes only. Planar perfusion imaging uses 78453 (single) or 78454 (multiple), and PET perfusion uses its own codes (see the PET section below).

Exercise Nuclear Stress Test CPT Codes: 78452 With 93015

An exercise nuclear stress test has two billable services: the cardiovascular stress test and the perfusion imaging. For a typical rest and stress study with treadmill exercise, the claim carries 78452 for the imaging and 93015, or its component codes, for the stress test. For a treadmill stress test without imaging, the CPT code is 93015, or its components, alone.

The 93015 Family: What Each Code Covers

Code	Part of the Stress Test It Reports	Who Usually Bills It
93015	The complete test: supervision, continuous ECG monitoring and tracing, and interpretation and report	One provider who performed every part, typically in a practice that owns the equipment
93016	Supervision only, without the interpretation and report	The supervising physician or practitioner
93017	Tracing only, without supervision or interpretation	The entity that owns the equipment and staff, for example the hospital
93018	Interpretation and report only	The physician who reads the stress ECG

The difference between 78452 and 93015 is the service. 78452 is the nuclear imaging and its interpretation. 93015 is the stress test itself, with its ECG monitoring and the stress ECG report. One does not include the other, so both appear on the claim when both are performed.

Can You Bill 78452 and 93015 Together?

Yes, when the same billing provider performed both complete services. The Medicare NCCI policy manual bundles the radiopharmaceutical injection into the nuclear medicine code and bundles the IV access, drug injection and routine ECGs into the stress test code, but it does not list the stress test among the services included in the perfusion imaging codes. Some commercial payers say so explicitly; Blue Cross and Blue Shield of Minnesota’s coding policy, for example, allows the stress test in addition to the nuclear study. As of the October 2026 quarter, CMS’s Medicaid NCCI files and the Medicare quarterly change report contain no edit pairing 78452 with 93015, 93016, 93017 or 93018, or with the stress agent and technetium tracer codes; edits change quarterly, so recheck for your date of service.

The more common error is billing 93015 when your provider did not perform the whole test. In a hospital, the hospital owns the treadmill, the ECG system and the staff, so it bills the tracing (93017). The cardiologist bills 93016 for supervising and 93018 for reading the stress ECG, never 93015. This is the same split as the routine ECG codes explained in our CPT 93000 guide.

What Is Bundled and Not Billed Separately

The 2026 Medicare NCCI policy manual, Chapter XI, and its radiology chapter (Chapter IX) list the pieces of a nuclear stress test that are not reported on their own:

• Injecting the radiotracer, including vascular access (36000) and injection codes (96360 to 96379), is part of the nuclear medicine code.
• The IV line and the pharmacologic agent’s injection or infusion are part of the stress test codes.
• Routine and rhythm ECGs (93000 to 93010 and 93040 to 93042) taken as part of the stress test are not billed separately.
• The history and limited exam before the test are part of the stress test. A separate E/M visit needs a significant, separately identifiable problem and modifier 25.

Lines billed against these rules usually come back as bundling denials such as CO-234, procedure not paid separately.

Lexiscan Stress Test CPT Code and Other Pharmacologic Agents

There is no separate CPT code for a Lexiscan stress test. A pharmacologic nuclear stress test uses the same procedure codes as an exercise test: 78451 or 78452 for the imaging, chosen by the protocol, and 93015 or its components for the stress test, because the stress test codes cover exercise or pharmacologic stress. The drug is added as a HCPCS Level II line when your entity bought and administered it.

Item	HCPCS Code	Billing Unit	Units for a Typical Dose
Regadenoson (Lexiscan)	J2785	0.1 mg	4 units for the labeled 0.4 mg dose
Adenosine	J0153	1 mg	Weight-based infusion; units equal the milligrams given
Dobutamine	J1250	250 mg	Weight-based infusion; units by the 250 mg increment
Technetium Tc-99m sestamibi	A9500	Per study dose	Usually 2 for a rest and stress study (one dose each)
Technetium Tc-99m tetrofosmin	A9502	Per study dose	Usually 2 for a rest and stress study
Thallium Tl-201	A9505	Per millicurie	The millicuries administered

According to the Lexiscan prescribing information, the drug is indicated for radionuclide MPI in patients unable to undergo adequate exercise stress, and the recommended dose is 0.4 mg given as a rapid IV injection. Medicare LCDs use similar language: CGS’s cardiovascular nuclear medicine LCD describes pharmacologic stress as the alternative when exercise cannot be performed. Document why pharmacologic stress was used: the patient could not exercise adequately (for example, orthopedic limits or deconditioning), or a finding such as left bundle branch block or a paced rhythm made exercise imaging unsuitable. That keeps the choice of stress method supported if the claim is reviewed.

Are the Drug and Tracer Paid Separately?

It depends on the setting:

• Physician office or IDTF. The practice that buys the drug and tracer bills them on its own lines. Keep the radiopharmaceutical invoice showing the agent, dosage, unit price and total; Wellpoint Federal’s billing article A56743 requires it in the medical record.
• Hospital outpatient department. The hospital reports the drug and tracer codes, but Medicare’s outpatient payment system (OPPS) packages them into the procedure payment. The regulation (42 CFR 419.2(b)(15)) packages drugs and radiopharmaceuticals that function as supplies in a diagnostic test, including pharmacologic stress agents. For 2026, CMS pays separately only for diagnostic radiopharmaceuticals whose per-day cost exceeds $655; the routine technetium MPI agents cost far less per day, so they remain packaged. 2026 also added HCPCS C9176, a $10 per-dose OPPS add-on for technetium-99m when at least 50 percent of the molybdenum-99 is domestically produced from non-HEU sources; it replaced Q9969 (SNMMI summary of the CY 2026 OPPS final rule).

Either way, the cardiologist reading a hospital study does not bill J2785 or the tracer, because the hospital supplied them.

Professional and Technical Components: Building the Claim by Setting

78452 has a professional component (the physician’s interpretation and report) and a technical component (camera, technologist, processing and supplies). Medicare prices both in the physician fee schedule, so who owns the equipment and who reads the study decides the modifier. In the CY 2026 relative value file, 78452 carries PC/TC indicator 1, so modifiers 26 and TC apply. 93015 carries indicator 4 (global test only), 93016 and 93018 carry indicator 2 (professional component only) and 93017 carries indicator 3 (technical component only), which is why the stress test is split with those codes rather than with modifiers.

Setting and Arrangement	Imaging	Stress Test	Drug and Tracer
Practice owns the camera; its cardiologist supervises and reads everything	78452 (global, no modifier)	93015	Practice bills, for example J2785 × 4 and A9500 × 2
Practice owns the camera; an outside cardiologist reads the SPECT	Practice: 78452-TC. Reader: 78452-26	Split by who did what (93016, 93017, 93018), or 93015 if the practice’s physician did all of it	Practice bills
Hospital outpatient department; the cardiologist supervises and reads	Cardiologist: 78452-26. Hospital: 78452 on its institutional claim	Cardiologist: 93016 and 93018. Hospital: 93017	Hospital reports; OPPS packages them

Supervision matters too. CGS’s LCD L33960 requires stress tests to be performed under the direct supervision of a physician and the nuclear components under general physician supervision. Wellpoint Federal’s L33560 allows supervision by a physician or a qualified non-physician practitioner, so check your MAC’s wording. Whoever bills 93016 should be the person the record names as supervising.

Echo and PET Stress Tests Use Different Codes

78452 is only for SPECT perfusion imaging. Two other stress imaging tests are coded differently.

Echo Stress Test CPT Codes

Stress echocardiography uses ultrasound, not a radiotracer. 93351 reports the complete stress echo, including the stress test with continuous ECG monitoring and physician supervision, so 93015 to 93018 are not added to it. 93350 reports the echo imaging and interpretation alone, for cases where the stress test portion is reported separately with the component codes. 93352 is an add-on for echo contrast; under OPPS it is not separately payable, and the contrast injection is not billed (NCCI Chapter XI). Noridian’s stress testing LCD (L34324) treats a stress echo done together with a myocardial perfusion stress test as not reasonable and necessary, so a patient rarely needs both for the same problem.

PET Myocardial Perfusion Codes

PET perfusion imaging has its own code set, revised in 2020. 78491 (single study) and 78492 (multiple studies) cover PET perfusion without a concurrently acquired CT scan; 78430 and 78431 are the single and multiple study versions with concurrently acquired CT. 78432 and 78433 cover combined perfusion and metabolic (viability) evaluation, and 78434 is an add-on to 78431 or 78492 for absolute quantitation of myocardial blood flow at rest and with pharmacologic stress. Medicare LCDs also restrict sequencing: the CGS and Wellpoint Federal LCDs deny a SPECT perfusion study performed after a diagnostic myocardial PET scan as not medically necessary.

Is CPT Code 78452 Covered by Medicare?

Yes, Medicare Part B covers 78452 when the study is reasonable and necessary. The national coverage determination for SPECT (NCD 220.12) is brief and leaves details such as frequency to the contractors, so the working rules come from the local coverage determinations (LCDs) and billing and coding articles that each Medicare Administrative Contractor (MAC) publishes for its own states. Check the policy for the MAC that processes your claims; the two below are examples.

Policy	MAC and States	Status Checked October 2026
LCD L33960, Cardiovascular Nuclear Medicine, with billing article A56494	CGS (Jurisdiction 15: Kentucky and Ohio)	In effect; current version effective January 29, 2026
LCD L33560, Cardiovascular Nuclear Medicine, with billing article A56743	Wellpoint Federal, formerly National Government Services (Jurisdictions 6 and K: IL, MN, WI, CT, ME, MA, NH, NY, RI, VT)	In effect; current versions effective April 1, 2026

CPT 78452 Medical Necessity

The CGS policy, LCD L33960, lists the situations in which cardiovascular nuclear imaging is indicated. Paraphrased, they include:

• Assessing the functional and prognostic significance of angina.
• Evaluating chest pain when the ECG is uninterpretable or equivocal, for example because of drugs, bundle branch block or left ventricular hypertrophy.
• Risk assessment in patients with known atherosclerotic heart disease who are asymptomatic or stable and have not been revascularized in the past two years.
• Looking for coronary disease in new heart failure or left ventricular systolic dysfunction, and separating ischemic from non-ischemic cardiomyopathy when catheterization is not planned.
• Evaluating perfusion before and after bypass surgery or other revascularization, and assessing a myocardial infarction.
• Preoperative assessment for non-cardiac surgery in defined higher-risk patients.

The same policy denies studies ordered on risk factors alone without symptoms or abnormal findings (treated as screening), tests that duplicate one already performed, tests whose results would not change management, SPECT after a diagnostic cardiac PET, and preoperative testing before low-risk surgery. Our guide to medical necessity denials covers how to work these when they happen.

ICD-10-CM Examples From a Medicare Billing Article

ICD-10-CM	Description
R07.9	Chest pain, unspecified
R07.89	Other chest pain
R06.02	Shortness of breath
R94.31	Abnormal electrocardiogram
I20.9	Angina pectoris, unspecified
I25.10	Atherosclerotic heart disease of native coronary artery without angina pectoris
I25.119	Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris
Z95.5	Presence of coronary angioplasty implant and graft
Z01.810	Encounter for preprocedural cardiovascular examination

Two cautions. First, a code on the list does not guarantee coverage; article A56743 says so, and the indication still has to fit the LCD. Second, common cardiology symptoms are not always on the list: palpitations (R00.2) and syncope (R55) are not in A56743’s perfusion group. The same article asks you to use Z01.810 for a preoperative study only when the result is negative, and to code the findings when it is positive. For the wider diagnosis picture, see our cardiology ICD-10 codes guide.

Documentation That Supports the Claim

• The order from the treating practitioner, with the clinical question: symptoms, ECG findings, prior testing and how the result will guide management.
• The protocol: which studies were acquired, on which dates, and with which tracer and dose.
• For pharmacologic stress, the agent, dose and the reason the patient could not exercise.
• The names of the supervising practitioner and of each interpreting physician.
• A signed interpretation for the perfusion study and, when billed, a separate stress ECG report.
• Dates and results of earlier stress tests, cardiac imaging or revascularization, so a reviewer can see the study is not a duplicate.

What Medicare Pays for 78452

Under the physician fee schedule, Medicare pays the global, professional (-26) and technical (-TC) amounts separately, each adjusted for your locality. The technical component carries most of the value because it covers the camera, the technologist and the processing. Pull your 2026 locality amounts for 78452 and the 93015 family from the CMS Physician Fee Schedule Look-up Tool rather than relying on national figures quoted online. In a hospital outpatient department, the hospital is paid an OPPS rate for the scan with the drug and tracer packaged in, while the cardiologist is paid the professional component.

Does CPT 78452 Require Prior Authorization?

For Original Medicare, generally no. CMS’s prior authorization program for hospital outpatient services covers procedures such as blepharoplasty, cervical fusion and facet joint interventions, and the WISeR model (launched January 2026 in six states) targets services such as nerve stimulators and epidural steroid injections. Neither lists myocardial perfusion imaging. Coverage is decided after the fact, against the LCD.

Medicare Advantage, Medicaid managed care and commercial plans are different. Many send nuclear cardiology through a radiology benefit manager. For example, Evolent’s scope of service for AmeriHealth Caritas VIP Care in Louisiana (a Medicare D-SNP, effective March 2026) lists myocardial perfusion imaging; Carelon reviews nuclear cardiology for Premera; and UnitedHealthcare Community Plan of Maryland lists 78451 and 78452 on its radiology prior authorization code list. Programs differ by plan, state and product, so check each member’s plan before scheduling.

• Authorize the code family, not just “a stress test.” An approval for 78451 may not cover a 78452 study, and an approval for SPECT will not usually cover PET; if the protocol changes, ask the plan or benefit manager to update the authorization before the claim goes out.
• Know the clock. Since January 1, 2026, Medicare Advantage plans and Medicaid and CHIP programs must decide expedited requests within 72 hours and standard requests within 7 calendar days under CMS’s Interoperability and Prior Authorization final rule (CMS-0057-F). Our guide to electronic prior authorization under CMS rules covers the 2027 API requirements.
• Medicare’s AUC program no longer applies. CMS paused the appropriate use criteria program and rescinded its regulation in the CY 2024 fee schedule rule, effective January 1, 2024, so Medicare claims should not carry AUC consultation codes or modifiers (CMS AUC program page). Commercial benefit managers still apply their own clinical criteria at authorization.

Missing or mismatched authorizations are a common cause of cardiology denials; our article on cardiology denial management shows how to track them back to the front desk.

Before You Submit: A Nuclear Stress Test Claim Check

Each item below starts ticked as the standard every claim should meet. Untick anything the chart in front of you does not show; whatever is unticked is the fix before the claim goes out.

1. The imaging code matches the protocol: 78452 only when two or more SPECT studies were acquired, reported once even across two days; 78451 for a single study.
2. The stress test codes match who did what: 93015 only when your provider supervised, traced and read the stress test; otherwise 93016, 93017 and 93018 as performed.
3. Modifier 26 or TC matches the setting and the reader, and no 26 or TC is appended to the 93015 family.
4. Drug units equal the documented dose divided by the HCPCS billing unit (0.4 mg regadenoson = J2785 × 4), and the drug is billed only by the entity that supplied it.
5. Tracer units match the doses given, per study dose for technetium agents or per millicurie for thallium, with the invoice in the record.
6. Nothing bundled is billed: no separate injection, IV, routine ECG or pre-test E/M lines, and no separate ejection fraction, wall motion or attenuation correction charge.
7. The diagnosis and record fit your MAC’s LCD, the study is not screening or a duplicate, and pharmacologic stress has a documented reason.
8. Authorization is on file for Medicare Advantage, Medicaid and commercial members whose plans require it, and it covers the code actually billed.

The Bottom Line

The 78452 CPT code is the multiple-study SPECT perfusion code, reported once per examination, with the stress test, the stress agent and the tracer on their own lines when they are billable. Most errors come from the protocol, the setting or the authorization, not the code itself. If those claims keep coming back, our cardiology medical billing services team can take over coding, authorization tracking and denial follow-up for your nuclear lab.

Frequently Asked Questions

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Sources: CMS Medicare Coverage Database: LCD L33960, Cardiovascular Nuclear Medicine (CGS, version effective January 29, 2026); LCD L33560 and billing and coding article A56743, Cardiovascular Nuclear Medicine (Wellpoint Federal, versions effective April 1, 2026); LCD L34324, Cardiovascular Stress Testing (Noridian, version effective October 16, 2025). CMS, Medicare NCCI Policy Manual, Chapters IX and XI (revised January 1, 2026). CMS, Medicaid NCCI procedure-to-procedure files and Medicare NCCI quarterly change report (October 2026 quarter). CMS, CY 2026 Physician Fee Schedule relative value file RVU26D (October 2026). CMS, HCPCS Level II file (October 2026). First Coast Service Options, Appropriate drug billing, Part B. FDA, Lexiscan (regadenoson) prescribing information. 42 CFR 419.2(b)(15). SNMMI, CMS Releases Final CY 2026 OPPS: Implications for Nuclear Medicine (November 24, 2025). CMS, Appropriate Use Criteria Program (updated March 10, 2026). CMS, Prior Authorization Metrics Reporting Overview, CMS-0057-F. MedLearn Publishing, cardiology coding questions on 78451 and 78452 (CPT 2025). Blue Cross and Blue Shield of Minnesota, Myocardial Perfusion (Cardiovascular Stress Test) coding policy 018 (December 1, 2023). Payer program examples: Evolent scope of service for AmeriHealth Caritas VIP Care Louisiana (March 2026); Premera, Carelon Medical Benefits Management; UnitedHealthcare Community Plan of Maryland radiology prior authorization code list.

Published by the Health Med Affairs editorial team. Health Med Affairs provides medical billing, coding, credentialing, and clinical documentation support to U.S. physician practices. This article is educational information, not legal advice and not coding advice for a specific claim; payer contracts and state laws vary.