CPT code 76770: Retroperitoneal ultrasound billing guide 2026

Key takeaways

CPT code 76770 reports a complete retroperitoneal ultrasound of the kidneys, aorta, common iliac artery origins, and inferior vena cava.

A study of the kidneys and urinary bladder also counts as complete when the history points at urinary tract disease.

Medicare’s 2026 national allowance is $106.21 global, $34.07 for the professional component, and $72.15 for the technical component.

Three ICD-10 codes often paired with 76770, including R59.0 and R19.09, are missing from Palmetto’s A55336 covered list.

NCCI treats 76700 as the comprehensive code, so any bypass modifier belongs on 76770 rather than on 76700.

CPT code 76770 bills a complete retroperitoneal ultrasound: kidneys, abdominal aorta, common iliac artery origins, and inferior vena cava. One word decides the claim, and that word is complete. Leave a structure out of the report and the study belongs on 76775 instead.

Medicare’s 2026 national allowance for the global service is $106.21, and two thirds of that sits in the technical component. Scope, diagnosis code, and modifier all have to agree before the claim goes out, or the payer sends it back. Start with what counts as complete, because every other decision on the claim follows from it.

CPT code 76770 covers four structures, not one

A complete retroperitoneal ultrasound means real-time scans of the kidneys, the abdominal aorta, the common iliac artery origins, and the inferior vena cava.

Any retroperitoneal abnormality the sonographer demonstrates goes in the report as well. The AMA descriptor reads: Ultrasound, retroperitoneal (eg, renal, aorta, nodes), real time with image documentation; complete.

There is a second route to complete, and it is the one most renal studies take.

When the history points at urinary tract disease, kidneys plus urinary bladder also counts as a complete retroperitoneal ultrasound. That is why a renal survey with bladder views codes to 76770 rather than 76775.

So a supportable 76770 report addresses each of the following:

• Kidneys, both sides – size, echogenicity, cortical thickness, and the collecting system
• Abdominal aorta – diameter, wall appearance, and any aneurysm
• Common iliac artery origins – where the aorta divides
• Inferior vena cava – patency, diameter, and respiratory variation
• Any retroperitoneal abnormality shown – enlarged nodes, a mass, or a fluid collection
• Urinary bladder – on the urinary tract route, in place of the vascular survey

Medicare adds a limit on top of that. Billing and Coding Article A55336 (companion to LCD L34577) expects 76770, 76775, and 76776 only when the exam stayed inside the retroperitoneum.

If the sonographer also looks at the gallbladder, liver, or spleen, the study has become an abdominal ultrasound and bills as 76700 or 76705.

Nor can you have it both ways. The A55336 article says plainly that billing a retroperitoneal study and an abdominal study together is not appropriate when the exam simply expanded. One study, one code.

Real-time image documentation is part of the descriptor, not an extra. Stored images have to correspond to the structures the report discusses.

A narrative with no images attached does not meet the definition, however thorough the narrative is.

Choosing between 76770 and 76775 is worth $45 a study

Bill 76770 when the report covers the full retroperitoneal survey, and 76775 when it covers one or two structures.

That single decision moves $45.42 on the 2026 national allowance, which is exactly why auditors look at it. The choice is not a judgment call, though. It is settled by what the report documents.

Read the report before you pick. Findings for kidneys, aorta, iliac origins, and inferior vena cava support 76770, and so does a kidneys-plus-bladder study on a urinary indication.

A note that only addresses the right kidney after a stone treatment is a 76775. Upcoding that study is the single easiest error for a payer to spot, because the report says what was examined.

Medicare only pays 76770 when the diagnosis is on the list

Medical necessity drives more 76770 denials than any other cause, and the diagnosis code decides it. Palmetto GBA lists 797 ICD-10-CM codes that support a retroperitoneal ultrasound in Article A55336.

Several codes that coding round-ups routinely pair with 76770 are not among them.

Two caveats before you rebuild your diagnosis crosswalk around this. A55336 belongs to Palmetto GBA. It applies in jurisdictions J and M, covering Alabama, Georgia, Tennessee, South Carolina, Virginia, West Virginia, and North Carolina.

Other contractors may publish no policy at all for retroperitoneal ultrasound, so confirm your own before you rely on the list.

The pattern travels even where the policy does not. Unspecified codes fail medical necessity far more often than specific ones.

If you are pulling diagnoses from a shared ICD-10-CM code library, check the descriptor against the report rather than reusing last year’s favorite.

Your report has to prove the exam was complete

The report carries the claim. A payer reviewing 76770 wants proof that the study happened, that a physician read it, and that the order had a reason. Six items do that work.

• A signed interpretation – a finalized report with the reading physician’s signature or electronic attestation
• Stored images – views that match the structures the report discusses, held in the record or in PACS
• Every structure addressed – kidneys, aorta, iliac origins, and inferior vena cava, or the kidneys and bladder on a urinary indication
• An order from the treating physician – written or electronic, with the clinical reason on it
• A diagnosis that matches – the referring diagnosis and the ICD-10-CM code on the claim have to agree
• Date and place of service – the encounter date, plus place of service 11 for the office or 22 for hospital outpatient

One phrase deserves a note. “Limited by body habitus” is acceptable when it is accurate, and it does not knock the study down to 76775.

What it cannot do is stand in for a structure nobody tried to image. Document the attempt, then document why the view failed.

Modifier 26 and TC split one payment between two owners

Which modifier you use depends on two questions: who owns the machine, and who reads the study. If the answer to both is your practice, you bill 76770 with no modifier at all and collect the global amount.

Modifier 26 and modifier TC never appear on the same line from the same provider. Between them they equal the global service, so billing both is billing the same work twice.

Modifier 52 also deserves a second look before you use it. If the sonographer only managed one or two structures, the honest answer is usually 76775 rather than a reduced 76770. Reach for 52 when a genuinely complete study was interrupted.

76770 pays $106.21 in 2026, and the split matters

Medicare prices 76770 from relative value units. Multiply the total RVUs by the conversion factor, then adjust for your locality’s geographic practice cost indices.

The national figures below come from the 2026 relative value file at the $33.4009 conversion factor.

Set the three 76770 rows next to each other and the shape of the code becomes obvious. The equipment and the sonographer carry most of the value, and the read carries the rest.

There is no facility global rate for 76770, which surprises people. The fee schedule marks the facility practice expense as not applicable. In a hospital outpatient department the physician bills 76770-26 for $34.07, and the hospital is paid separately under the outpatient system.

One more wrinkle is new enough that most fee tables miss it. Medicare runs two conversion factors in 2026: $33.4009 for most billers, and $33.5675 for qualifying alternative payment model participants.

The same 76770 claim allows $106.21 under the first and $106.74 under the second. Check the CMS fee schedule look-up tool for your locality and your status.

Commercial payers usually sit above Medicare, often by 10% to 40%, but only your contract says by how much. Compare each remittance against the contracted rate rather than against the Medicare figure.

NCCI bundles 76770 into the abdominal ultrasound, not the reverse

The National Correct Coding Initiative, or NCCI, publishes quarterly edits that say which code pairs can go out together. For 76770 the pair that matters is 76700, the complete abdominal ultrasound. The two studies overlap, because a complete abdominal exam already views the kidneys and the upper aorta.

Direction is where coders trip. In the procedure-to-procedure edit, 76700 sits in column one as the comprehensive code and 76770 sits in column two. So when both go out on the same date of service, 76770 is the line that drops.

That also settles where the modifier goes. If the two studies were genuinely separate and separately ordered, the NCCI-associated modifier belongs on 76770, the column two code. Modifier 59 or one of the X modifiers, XE, XP, XS, or XU, tells the payer which circumstance applies. Appending it to 76700 has no effect.

Even then, expect scrutiny. A55336 says it is not appropriate to bill a retroperitoneal study alongside an abdominal one when the retroperitoneal exam simply expanded mid-scan. Two orders, two indications, and two reports are what make the pair defensible.

76770 and 76775 never go out together for the same patient on the same date. Complete or limited, pick one. Edit pairs change every quarter. Pull the current table from the NCCI edit files rather than trusting any list in an article, including this one.

Follow a 76770 claim from the order to the remittance

Most 76770 problems are baked in long before anyone opens the billing screen. Here is the path a clean one takes.

1. The order arrives. The treating physician sends a written or electronic order naming the clinical reason, such as stage 3b chronic kidney disease. That reason becomes the diagnosis on the claim.
2. The scan happens. The sonographer works through the full survey and saves images for each structure, including the ones that would not visualize.
3. The report is finalized. The reading physician addresses every structure by name and signs off. This is the document that decides 76770 versus 76775.
4. Coding and scrubbing. A coder reads the report and picks the code from what it says. Then they match the ICD-10-CM code to the order and check the modifier against equipment ownership.
5. Submission and remittance. The claim goes out as an 837P through the clearinghouse. The remittance comes back with either a payment or a CARC code explaining the denial.

Worked through with numbers, it looks like this. A nephrologist orders a renal ultrasound for stage 3b chronic kidney disease. The sonographer scans both kidneys and the bladder, and the radiologist reports both. The history points at urinary tract disease, so the study is complete.

The practice owns the scanner and employs the radiologist, so the claim goes out globally with no modifier. Code 76770, diagnosis N18.32, place of service 11. Allowed amount before locality adjustment: $106.21. Every step was routine, and that is the point.

Five denials cause most of the rework on 76770

Retroperitoneal ultrasound denials cluster tightly. Each of the five below has a fix that belongs in the workflow rather than in the appeal queue.

Run this check before the claim goes out

Eight questions, answered in order, catch nearly all of the above:

• Does the report address every retroperitoneal structure, or the kidneys and bladder?
• Did the exam stay inside the retroperitoneum, or did it become an abdominal study?
• Are stored images attached for the structures discussed?
• Is the interpretation signed?
• Does an order exist, with a clinical reason on it?
• Is the ICD-10-CM code specific, and is it on your MAC’s covered list?
• Does the modifier match who owns the equipment and who read the study?
• Is any other imaging code on the same claim, and does it trigger an edit?

Practices that run this check as part of submission rather than as an audit afterwards see the difference in first-pass acceptance. A clean claim costs a couple of minutes up front and saves a fortnight of chasing.

How Pabau keeps 76770 claims clean before they leave

In most practices the claim gets rebuilt by hand. Someone retypes the CPT code onto the form, then opens a second window to look up the diagnosis. The missing membership number only surfaces after the payer rejects the file.

Practice management software like Pabau closes that loop inside the record. The code attached to the service lands on the charge line, and the diagnosis slots seed from the client’s recorded problem list.

Built-in ICD-10-CM and CPT libraries let a coder confirm a descriptor without leaving the claim. Required fields are validated before the send button unlocks, so a claim missing an authorization number does not go anywhere.

US claims route out through Claim.MD. That gives you real-time eligibility checks, claim status tracking, and remittance posting in the same place as the client record.

When a 76770 claim comes back denied, the CARC code sits next to the visit it belongs to. Your biller can work the appeal without opening a second system. Pabau’s cleaner claims management is built around that single record.

Send 76770 claims with the fields already filled

Pabau’s claims management fills the CMS-1500 from the client record and checks the required fields before the claim can be sent. US claims route through Claim.MD for eligibility checks, claim status, and remittance posting.

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Conclusion

76770 is not a difficult code. It is a strict one. The report decides whether you may bill it, the diagnosis decides whether you get paid for it, and the modifier decides how much lands.

If you change one habit after reading this, make it the diagnosis. Coders reach for the unspecified code because it is quick, and unspecified codes are the ones that fall off covered lists. Pull the specific one from the report instead, and a large share of your medical necessity denials stop happening.

The rest is process. Same checks, same order, every claim. Book a demo to see how Pabau builds the 76770 claim from the record and tracks it through to the remittance.

Continue your research

Working through a stack of denied imaging claims? Denial management in healthcare sets out how to triage denials by cause and stop the repeat offenders.

Not sure what your remittance is telling you? Electronic remittance advice explains how to read an ERA and spot an underpayment against your contracted rate.

Wondering where a claim goes after you hit send? Medical claims clearinghouse walks through the route to the payer and the checks that catch errors first.

Need the file format behind an electronic claim? The 837 electronic claim file breaks down what each loop carries and where imaging claims fail validation.

Comparing clearinghouses for a US practice? The Claim.MD clearinghouse guide covers eligibility checks, remittance processing, and payer enrollment.

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