CPT code 71550 – MRI chest without contrast

Key takeaways

CPT code 71550 reports a chest MRI with no contrast at any point in the session. Once gadolinium is injected, the study becomes 71551 or 71552.

When pre- and post-contrast sequences run in one session, bill 71552 alone rather than 71550 plus 71551.

Most commercial payers and many Medicaid managed-care plans require prior authorization for 71550, so request it before the scan.

The 2026 national Medicare non-facility rate for the global 71550 is about $333, based on 9.97 total RVUs.

Pabau’s claims management software submits HIPAA-compliant 837P claims through its Claim.MD clearinghouse integration.

CPT code 71550 is a chest MRI with no contrast

The American Medical Association (AMA) defines CPT code 71550 as “Magnetic resonance imaging, chest (eg, for evaluation of hilar and mediastinal lymphadenopathy); without contrast material(s).” It sits in the Chest subsection of Diagnostic Radiology, which runs from 71045 to 71555.

The code covers acquiring and interpreting a non-contrast MRI of the thoracic cavity. Use it only when no gadolinium is given at any point in the session. If contrast goes in, the study becomes 71551 or 71552.

What 71550 covers, and when radiologists choose it

71550 covers a non-contrast MRI of the whole chest. That includes the mediastinum, hilar regions, pleural spaces and nearby soft tissues.

Radiologists choose it when the clinical question doesn’t need gadolinium. Sometimes the patient can’t have contrast because of renal impairment or a prior reaction. Other times, anatomy rather than enhancement is the goal.

Orders billed under 71550 commonly document these indications:

• Mediastinal masses or mediastinal lymphadenopathy where CT findings are inconclusive
• Hilar lymphadenopathy workup, including suspected sarcoidosis or lymphoma staging
• Pulmonary lesions that need more soft-tissue detail than CT provides
• Chest wall or pleural disease, including fibrous tumors and mesothelioma staging
• Superior sulcus (Pancoast) tumor evaluation for surgical planning
• Non-contrast soft-tissue assessment of the mediastinum when gadolinium is contraindicated

Read “without contrast material(s)” as the billing criterion, not as optional phrasing. If gadolinium is injected at any point, the code changes. Billing 71550 after an injection is a coding error that a payer audit will find.

71550 vs 71551 vs 71552: Contrast decides the code

All three chest MRI codes share the same region and modality. They differ only on contrast. Use 71550 with no contrast, 71551 with contrast only, and 71552 when images are taken before and after contrast in one session.

The decision chart below walks through the same choice, starting from what the radiology report says.

Under CMS National Correct Coding Initiative (NCCI) edits, 71550 and 71551 should not be reported together for one session. Submitting both separately triggers an edit denial. When both sequences run in one session, bill 71552 alone.

MRI vs CT: Why payers often want 71250 first

CPT code 71250 covers a CT scan of the thorax without contrast, not an MRI. Coders often see orders for both on the same patient. Each modality needs its own clinical rationale in the record.

Many commercial payers apply step therapy. They expect a CT first and deny the MRI unless the notes show why CT was insufficient or contraindicated. The ordering physician’s notes must state that rationale for 71550 to pass medical necessity review.

Documentation that keeps a 71550 claim clean

A payer reviewer should be able to follow every 71550 claim from clinical question to imaging result. Incomplete records are a common and preventable denial cause. A clean claim checklist built into the ordering workflow stops them early.

• Ordering provider NPI: The ordering physician’s NPI must appear on the claim. Medicare requires it, and most commercial payers follow the same rule.
• Clinical indication: The order and report must state the specific clinical question. Write “evaluation of mediastinal lymphadenopathy identified on CT,” not “chest imaging requested.”
• Contrast status confirmed: The radiologist’s report must state “without contrast” or “no contrast administered.” Vague wording such as “standard protocol” is not enough.
• Body region specified: The order must name the chest. A generic MRI order without an anatomical region often draws an additional documentation request.
• Signed final report: The interpreting radiologist must sign the final report. Preliminary or unsigned reports cannot support billing.
• Medical necessity diagnosis: At least one ICD-10-CM code that supports medical necessity must be on the claim. The pairing table below lists common choices.
• Prior authorization number: If the payer required authorization, enter the number in item 23 of the CMS-1500 or the matching 837P field.

Which ICD-10 codes support medical necessity for 71550

Every 71550 claim needs a diagnosis from the ICD-10-CM codes that matches the ordering physician’s notes and the radiology report. Check the pairing against any Local Coverage Determination (LCD) your MAC applies. Not every diagnosis establishes medical necessity under every payer’s policy.

Use a nonspecific code such as R91.8 only until a more specific diagnosis is documented. After that, the claim should carry the specific code. LCDs vary by jurisdiction, so check the CMS Medicare Coverage Database before you submit.

Prior authorization: Get it before the scan, not after

Most commercial payers and many Medicaid managed-care organizations require prior authorization for 71550. Make a PA check a standard part of insurance eligibility verification before any chest MRI is booked.

• eviCore Healthcare: Several major commercial payers, including some Blue Cross Blue Shield affiliates, use eviCore for imaging review. Expect to supply the clinical indication, prior imaging results and the reason contrast isn’t being used.
• Medicare: Traditional Medicare (Parts A and B) does not require prior authorization for Part B outpatient diagnostic imaging. Medicare Advantage plans set their own PA rules, which can differ a lot.
• Medicaid: State programs vary. The Centene Texas Medicaid Utilization Review Matrix (2026) lists 71550 as needing utilization review before approval. Check the state’s managed-care policy directly.
• Documentation to include: Send the ordering physician’s notes, prior imaging reports (especially CT chest results) and any specialist notes that support MRI over CT.

Many payers deny retro-authorization requests, and the appeal window after a retro-denial is short. A written prior authorization process gets the request out with the order, not on scan day.

Medicare pays about $333 for 71550 in 2026

Medicare pays 71550 under the 2026 Medicare Physician Fee Schedule (MPFS), with separate non-facility and facility rates. The imaging center or hospital usually bills the technical component (TC). The interpreting radiologist bills the professional component with modifier 26, and the global code covers both.

The global figure is a national amount before locality adjustment. Geographic Practice Cost Indices (GPCIs) move it up or down, so high-cost markets such as San Francisco or Manhattan pay more. Qualifying APM participants use a slightly higher conversion factor of $33.5675.

Check the TC and 26 splits, and your locality rate, in the CMS Physician Fee Schedule lookup tool before using any figure for projections. CMS updates rates each January 1 through the MPFS final rule, usually published in November. Confirm the billing locality on the claim before you submit.

Why 71550 claims get denied, and how to fix each one

71550 claims fail for a predictable set of reasons, and most can be fixed before submission. The table pairs each common denial pattern with its fix. A structured denial management workflow helps your team resolve repeat issues before they reach the payer.

Sending 71550 through the 837P electronic claim submission workflow helps catch missing required fields and eligibility problems before the claim reaches the payer.

Modifiers that split or adjust a 71550 claim

Modifiers tell the payer about circumstances that change how it pays a 71550 claim. The wrong modifier, or a missing one, leads to a denial or a payment error that can trigger a post-payment audit.

The TC and 26 split is the most common modifier scenario for 71550 in hospital-based radiology. A provider who bills the global code should not also bill TC or 26 for the same study, because that pays the same work twice.

Pabau’s claims management software pre-fills the claim form from the patient record and checks that required fields are complete before submission.

Before you submit: A six-point 71550 checklist

A 71550 claim moves from the order to authorization, the scan, the signed report, coding and submission. Run these checks at the coding step, while a fix still takes minutes.

• The signed report says no contrast was given, in those words.
• The order explains why MRI was chosen over CT, or why CT fell short.
• The ICD-10-CM code is active for the date of service and matches the report.
• The ordering provider’s NPI is on the claim.
• The prior authorization number is in item 23, if the payer required one.
• TC or 26 is appended when only one component is billed, and never alongside the global code.

How claims management software keeps 71550 claims moving

In many imaging practices, staff still assemble each 71550 claim by hand. They copy the code, the diagnosis and the authorization number from separate screens. A missing field only shows up when the payer rejects the claim.

Pabau, the practice management platform we build, does that assembly from the patient record. It runs US eligibility checks, validates required fields such as the authorization number, and sends the claim through Claim.MD.

Coding decisions stay with your coders. What changes is that fewer claims come back for missing data, and claim-status tracking shows where each one sits.

Send complete 71550 claims the first time

Pabau pre-fills claims from the patient record and checks required fields before they go to Claim.MD, so fewer imaging claims bounce back for missing data.

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Conclusion

Treat the signed radiology report as the source of truth for 71550. If it states that no contrast was given, and the order explains why MRI beat CT, the code choice defends itself on review.

When either detail is vague, fix it before the claim leaves the practice. A corrected claim or an appeal costs weeks, while a question to the radiologist costs minutes.

Pabau’s claims management software submits claims through Claim.MD, with US eligibility checks, claim-status tracking and required-field validation before the claim is sent. Book a demo to see how it fits your imaging billing workflow.

Continue your research

Getting denials you can’t decode? Denial codes in medical billing covers the most common CARC reason codes and how to respond to each one.

Want to see how clearinghouse submission works end to end? Medical claims clearinghouse guide explains the 837P transaction flow and how clearinghouses validate claims before payer adjudication.

Reconciling a 71550 payment? Electronic remittance advice (ERA) explains how to read 835 files and post payment adjustments on imaging claims.

Billing a chest CT with contrast instead? CPT 71260 covers CT of the thorax with contrast and how it differs from 71250.

Comparing tools for imaging authorizations? Best prior authorization software ranks platforms that help practices submit and track authorization requests.

Frequently asked questions