Renal artery stenosis is the leading correctable cause of secondary hypertension and a frequent driver of ischemic kidney disease. It is also one of the most miscoded vascular diagnoses in nephrology, cardiology, and interventional radiology billing.
Renal artery stenosis has no single ICD-10 code. The condition codes by cause. Atherosclerotic stenosis, fibromuscular dysplasia, and congenital stenosis each map to a different code in a different chapter. The associated hypertension carries its own code.
This guide covers every billable renal artery stenosis code, the etiology that drives each selection, the renovascular hypertension pairing, the transplant pitfall, and the stent-coverage rule that produces the most expensive denials. Understanding these core nephrology ICD-10 codes is essential for maintaining compliance and preventing revenue leakage at every stage of renal care.
What Is the ICD-10 Code for Renal Artery Stenosis?
The default ICD-10 code for renal artery stenosis is I70.1 — Atherosclerosis of renal artery. I70.1 covers atherosclerotic stenosis, which causes roughly 90% of renal artery stenosis cases.
I70.1 lists “acquired renal artery stenosis,” “stenosis of renal artery,” and “arteriosclerosis of renal artery” among its synonyms. The 2026 edition retained I70.1 with no change, effective October 1, 2025.
Renal artery stenosis is not one diagnosis with one code. The correct code depends on the documented cause. Atherosclerotic stenosis maps to I70.1. Fibromuscular dysplasia maps to I77.3. Congenital stenosis maps to Q27.1.
I70.1 applies only to adult patients aged 15 to 124 years. A pediatric stenosis cannot use I70.1 and routes to the congenital or fibromuscular codes instead.
Note: I70.1 has no laterality character. A single I70.1 reports right, left, or bilateral atherosclerotic renal artery stenosis. Coders searching for a right or left renal artery stenosis ICD-10 code will not find one in the I70.1 entry.
Complete Renal Artery Stenosis ICD-10 Code Table
ICD-10 renal artery stenosis codes split into two groups: the etiology codes that name the cause of the narrowing, and the associated codes that capture the hypertension and downstream kidney effects. The table below shows both.
Etiology Codes: The Cause of the Stenosis
Use the code that matches the documented cause of the renal artery stenosis. Atherosclerosis is the most common cause and the highest-volume code.
| Code | Description | When to Use | Billable |
|---|---|---|---|
| I70.1 | Atherosclerosis of the renal artery | Atherosclerotic stenosis; adult patient; ~90% of RAS | Yes |
| I77.3 | Arterial fibromuscular dysplasia | Fibromuscular dysplasia of the renal artery; younger patients | Yes |
| Q27.1 | Congenital renal artery stenosis | Stenosis present at birth; POA-exempt | Yes |
| I77.73 | Dissection of the renal artery | Stenosis or occlusion from renal artery dissection | Yes |
| I72.2 | Aneurysm of the renal artery | Renal artery aneurysm; distinct from stenosis | Yes |
| I75.81 | Atheroembolism of the kidney | Cholesterol or atheromatous embolism to the kidney | Yes |
I77.3 is not renal-specific. The same code reports fibromuscular dysplasia of the carotid or other arteries. The renal artery is the most common site.
Associated and Downstream Codes
These codes capture the hypertension and kidney effects that accompany renal artery stenosis. They report alongside the etiology code, not in place of it.
| Code | Description | Clinical Context |
|---|---|---|
| I15.0 | Renovascular hypertension | Hypertension caused by the renal artery stenosis |
| N28.0 | Ischemia and infarction of the kidney | Reduced perfusion or infarction from the stenosis |
| N18.- | Chronic kidney disease, by stage | Ischemic nephropathy progressing to CKD |
| T86.1- | Complications of a transplanted kidney | Stenosis in a transplanted renal artery |
| Z94.0 | Kidney transplant status | Reported with transplant renal artery stenosis |
The associated codes carry the clinical consequences that justify intervention. The stent coverage rule depends on at least one of these codes appearing alongside the etiology code.
Coding RAS by Etiology: Atherosclerotic, Fibromuscular, Congenital
The etiology drives the code. A coder cannot select a renal artery stenosis code without the documented cause. The three primary causes map to three separate codes in three separate chapters.
Atherosclerotic Stenosis — I70.1
I70.1 applies when atherosclerosis causes the renal artery stenosis. Atherosclerotic stenosis affects older adults, often with diabetes, hyperlipidemia, or coronary disease. Imaging shows calcified or ostial plaque.
Use I70.1 when the provider documents atherosclerotic renal artery stenosis or attributes the stenosis to atherosclerosis. The single code reports unilateral or bilateral disease.
Fibromuscular Dysplasia — I77.3
I77.3 applies when fibromuscular dysplasia causes the stenosis. Fibromuscular dysplasia is an idiopathic, nonatherosclerotic disease affecting younger patients, predominantly women. Imaging shows a “string of beads” pattern.
Use I77.3 when the provider documents fibromuscular dysplasia of the renal artery. The code captures the dysplasia regardless of which artery it affects, since I77.3 is not site-specific.
Congenital Stenosis — Q27.1
Q27.1 applies when the renal artery stenosis is present at birth. Congenital renal artery stenosis is rare and often detected in childhood or adolescence through a hypertension workup.
Use Q27.1 when documentation supports the congenital nature of the stenosis. Q27.1 is exempt from present-on-admission reporting.
Etiology Decision Table
| Provider Documentation | Correct Code |
|---|---|
| “Atherosclerotic renal artery stenosis” | I70.1 |
| “Renal artery stenosis due to fibromuscular dysplasia” | I77.3 |
| “Congenital renal artery stenosis” | Q27.1 |
| “Renal artery stenosis,” cause not stated | Query the provider |
The bottom row matters. Renal artery stenosis without a documented cause has no clean default. Query the provider before forcing I70.1 onto a chart that does not support atherosclerosis.
Renovascular Hypertension (I15.0) and the “Code Also” Rule
Renovascular hypertension is the hypertension caused by renal artery stenosis. The code is I15.0 — Renovascular hypertension. I15.0 captures high blood pressure secondary to renal artery obstruction or compression.
I15.0 is a secondary hypertension code. Category I15 carries a “code also” instruction for the underlying condition. The renal artery stenosis cause reports alongside I15.0.
The Two-Code Pattern for Renovascular Hypertension
Renovascular hypertension caused by renal artery stenosis reports two codes:
- I15.0 — the renovascular hypertension
- The etiology code — I70.1, I77.3, or Q27.1 for the stenosis
A worked example: atherosclerotic renal artery stenosis causing hypertension reports I15.0 and I70.1. The sequencing follows the encounter focus, covered in the next section.
Do Not Default to I10
Essential hypertension (I10) is the wrong code when renal artery stenosis causes the hypertension. I10 reports primary hypertension with no identified cause. Documented renal artery stenosis establishes a secondary cause, which routes the hypertension to I15.0.
Coding I10 in a documented renovascular hypertension chart understates the clinical picture and misses the secondary etiology that drives workup and intervention.
Transplant Renal Artery Stenosis: Why I70.1 Is Wrong?
Transplant renal artery stenosis is a complication of a kidney transplant, not a native-vessel disease. The code comes from the transplant complication category T86.1-, not I70.1.
Stenosis at the anastomosis of a transplanted renal artery is the most common vascular complication after a kidney transplant. Coding it as I70.1 treats a transplant complication as native atherosclerosis, which is incorrect.
The Transplant Code Pattern
Transplant renal artery stenosis reports the transplant complication structure:
- T86.1- — complication of the transplanted kidney, including the stenosis
- Z94.0 — kidney transplant status
- I15.0 — renovascular hypertension, when the stenosis causes it
The native-vessel etiology codes (I70.1, I77.3, Q27.1) do not apply to a transplanted renal artery. Confirm whether the affected kidney is native or transplanted before selecting a code.
How to Sequence Renovascular Hypertension Diagnosis Codes Correctly?
Selecting the right codes is half the task. Sequencing them correctly is the other half. Renovascular hypertension claims fail when the cause-and-effect codes are ordered against the encounter focus.
Outpatient and inpatient settings apply different first-listed rules. Practices operating in both must apply the correct standard to each claim.
Outpatient Sequencing
In outpatient settings, the first-listed diagnosis is the condition chiefly responsible for the encounter. The choice between leading with the stenosis or the hypertension depends on the reason for the visit.
- A visit to manage renovascular hypertension lists I15.0 first, then the stenosis code.
- A visit to evaluate or treat the stenosis lists the stenosis code first, then I15.0.
- A renal artery intervention lists the stenosis code as the indication, with hypertension or ischemic nephropathy as additional codes.
Inpatient Sequencing
In inpatient settings, the principal diagnosis is the condition established after study to be chiefly responsible for the admission. An admission for renal artery stenting sequences the stenosis code per the circumstances of admission.
Reporting the Clinical Consequences
When the stenosis causes ischemic nephropathy or chronic kidney disease, add N28.0 or the applicable N18 stage code. These codes establish the severity that supports intervention and risk adjustment.
Documentation Requirements for Each Code
Documentation determines whether a renal artery stenosis claim survives a payer audit. Each code carries specific requirements that must be present at claim submission. Documentation cannot be added after a denial.
I70.1 — Atherosclerosis of Renal Artery
- Provider statement attributing the stenosis to atherosclerosis
- Imaging findings supporting atherosclerotic disease, such as duplex, CTA, MRA, or angiography
- Patient age within the adult range, since I70.1 excludes patients under 15
- Documentation of the affected kidney or bilateral involvement
- Provider signature with date of service
I77.3 — Fibromuscular Dysplasia
- Provider documentation of fibromuscular dysplasia as the cause
- Imaging showing the characteristic beaded or stenotic pattern
- Confirmation that the renal artery is the affected site
- Provider signature with date of service
Q27.1 — Congenital Renal Artery Stenosis
- Documentation supporting the congenital nature of the stenosis
- Location and severity of the stenosis described
- Associated hypertension or kidney involvement noted when present
- Provider signature with date of service
I15.0 — Renovascular Hypertension
- Documented causal link between hypertension and renal artery stenosis
- The underlying stenosis etiology code on the claim
- Blood pressure findings supporting the hypertension diagnosis
- Provider signature with date of service
Renal Artery Stenosis in Nephrology Patients
Renal artery stenosis in a nephrology practice is a perfusion problem with kidney-function stakes. The stenosis reduces renal blood flow, which drives ischemic nephropathy and progressive chronic kidney disease.
The coding stakes are higher in nephrology than in a general hypertension encounter. The stenosis, the hypertension, and the kidney damage each require capture to support the clinical picture and the risk-adjustment value.
Ischemic Nephropathy and CKD
When renal artery stenosis reduces perfusion enough to damage the kidney, the chart documents ischemia, infarction, or chronic kidney disease. Code the consequence alongside the stenosis.
- Acute ischemia or infarction routes to N28.0.
- Chronic kidney disease from chronic hypoperfusion routes to the applicable N18 stage code.
- The stenosis etiology code remains on the claim as the cause.
Bilateral Stenosis and Solitary Kidney
Bilateral renal artery stenosis, or stenosis affecting a solitary functioning kidney, raises both clinical urgency and reimbursement stakes. I70.1 reports bilateral atherosclerotic stenosis without a separate laterality code. Document the bilateral or solitary-kidney status to support the severity.
Many nephrology practices engage nephrology billing specialists to align the stenosis, hypertension, and CKD codes and reduce denial risk on renovascular claims.
The RAS-CKD-Hypertension Picture
A nephrology renovascular chart often carries three threads: the stenosis cause, the renovascular hypertension, and the ischemic kidney damage. The complete code set reports all three: the etiology code, I15.0, and N28.0 or the N18 stage.
CPT Codes Commonly Paired with Renal Artery Stenosis
The ICD-10 codes establish medical necessity for every CPT code billed in the same encounter. A renal artery stenosis claim clears review only when the diagnosis supports the imaging or intervention.
The CPT codes below appear frequently with renal artery stenosis diagnoses. The diagnosis selection affects whether each line clears medical necessity.
| CPT Code | Description | ICD-10 Pairing Notes |
|---|---|---|
| 93975 / 93976 | Duplex scan of renal vessels (complete/limited) | First-line noninvasive screen; supported by suspected RAS |
| 74175 | CT angiography, abdomen, with contrast | Images the renal arteries; supports the stenosis workup |
| 74185 | MR angiography, abdomen | Alternative noninvasive imaging for renal artery stenosis |
| 36251 / 36252 | Diagnostic renal angiography (unilateral/bilateral) | Definitive imaging; bundles flush aortography and pressures |
| 36253 / 36254 | Superselective renal angiography (unilateral/bilateral) | Second-order or higher selective catheterization |
| 37246 / 37247 | Transluminal angioplasty, renal artery (first/additional) | Angioplasty without stent; pair with the stenosis code |
| 37236 / 37237 | Renal artery stent placement (first/additional) | Stenting; subject to the LCD additional-code rule below |
CPT-ICD-10 Pairing Tip
Diagnostic renal angiography (36251 to 36254) is not separately reportable at the time of intervention when a prior angiogram already defined the anatomy. Reporting both would bill the diagnostic evaluation twice.
Medicare and Payer-Specific Billing Rules
The most expensive renal artery stenosis denials come from the stent coverage rule. Under the Medicare Non-Coronary Vascular Stents policy, I70.1 and I77.3 alone do not meet medical necessity for renal artery stenting.
Renal artery stent placement (CPT 37236 and 37237) requires an additional diagnosis code documenting a clinical consequence of the stenosis. The stenosis code by itself does not establish coverage.
The Additional-Code Requirement for Stenting
The Medicare policy requires a second code alongside I70.1 or I77.3 to support stent coverage. The additional code documents the clinical condition the stenosis causes, such as:
- Renovascular hypertension (I15.0) that is resistant or accelerated
- Ischemic nephropathy or declining kidney function
- Recurrent flash pulmonary edema attributed to the stenosis
A stent claim carrying I70.1 alone fails the limited coverage criteria. The fix is documenting and coding the clinical consequence that justifies the intervention.
MS-DRG Assignment
The renal artery stenosis codes group within the kidney and urinary tract DRG family. I70.1 maps to MS-DRG 698, 699, or 700, depending on the presence of a major complication, a complication, or neither.
Diagnostic Angiography Coverage
Diagnostic renal angiography (36251 to 36254) follows its own Medicare coverage article. The covered diagnosis list governs which renal artery stenosis and renovascular hypertension codes support the angiography claim. Confirm the active local coverage determination before submission.
Top Renal Artery Stenosis ICD-10 Claim Denial Reasons
Six denial patterns account for most preventable renal artery stenosis billing losses. Each has a specific root cause and a clear fix. These denials are the reasons why nephrologists consider hiring expert nephrology billing services.
Denial 1: Stent Claim With Only I70.1 or I77.3
The coder reports the renal artery stent (37236) with the stenosis code alone. The claim fails the Medicare additional-code requirement for stent coverage.
Fix: Add the clinical consequence code, such as I15.0 for renovascular hypertension or the ischemic nephropathy code, to meet the limited coverage criteria.
Denial 2: Hypertension Coded as I10 Instead of I15.0
The coder reports essential hypertension when documented renal artery stenosis causes the hypertension. The secondary etiology is missed.
Fix: Use I15.0 for renovascular hypertension and code the stenosis cause alongside it. Reserve I10 for primary hypertension with no identified cause.
Denial 3: Transplant Stenosis Coded as I70.1
The coder reports native-vessel atherosclerosis for a stenosis in a transplanted renal artery. The code misclassifies a transplant complication.
Fix: Use the transplant complication code from T86.1- with Z94.0 for transplant status. Do not use I70.1, I77.3, or Q27.1 for a transplanted kidney.
Denial 4: Wrong Etiology Code Selected
The coder defaults to I70.1 for fibromuscular dysplasia or congenital stenosis. The code contradicts the documented cause and the patient’s age.
Fix: Match the code to the documented etiology. Use I77.3 for fibromuscular dysplasia and Q27.1 for congenital stenosis, especially in younger patients.
Denial 5: Missing Imaging Documentation
The stenosis is coded, but the supporting imaging is absent from the chart. The duplex, CTA, MRA, or angiography result was not documented.
Fix: Require the imaging result in the chart before coding the stenosis. Import outside results with the date and findings into the encounter note.
Denial 6: Diagnostic Angiography Billed With Intervention
The coder reports diagnostic angiography at the time of stenting when a prior angiogram already defined the anatomy. The diagnostic evaluation is billed twice.
Fix: Report diagnostic angiography only when it informs the treatment decision in the same session. Do not rebill it when prior imaging established the pathology.
