ICD code S35.416D – Laceration of unspecified renal vein, follow-up

Key takeaways

S35.416D covers a laceration of a renal vein, side not documented, at a subsequent (follow-up) encounter after active treatment has ended.

The 7th character D is valid only once active treatment is complete. Using D during ongoing surgical or interventional care triggers denials.

Documenting the side moves the claim to S35.414D (right) or S35.415D (left), the codes payers expect when laterality is known.

Code also any associated open wound (S31.-), and add a Chapter 20 external cause code (V00-Y99) where the payer or state requires one.

In Pabau, the practice management software we build, claims management scrubs each claim for missing or invalid details before submission.

ICD-10 code S35.416D: Quick reference

ICD-10 code S35.416D is a valid, billable code in the FY2027 ICD-10-CM tabular list, effective October 1, 2026. It reports a laceration of a renal vein at a follow-up encounter when the record does not say which side was injured. It belongs to category S35, injury of blood vessels at abdomen, lower back and pelvis level (Chapter 19, codes S00-T88). Picking the right suffix here is the first step in the medical billing workflows that turn a follow-up visit into a paid claim.

What S35.416D covers: Code description and anatomy

Each kidney drains through a renal vein into the inferior vena cava. The left renal vein is the longer of the two and crosses in front of the aorta to reach the vena cava. The right renal vein is short and joins the vena cava almost directly.

Renal vein injuries are uncommon and usually follow penetrating abdominal or flank trauma, such as gunshot and stab wounds. They can also follow blunt deceleration injuries or occur during renal or retroperitoneal surgery.

Two details define S35.416D. The injury is a laceration, and the record does not state the side. Subcategory S35.41 splits renal vessel lacerations by vessel and side:

• S35.411-S35.413: Laceration of the right, left, or unspecified renal artery.
• S35.414: Laceration of right renal vein.
• S35.415: Laceration of left renal vein.
• S35.416: Laceration of unspecified renal vein. Use it only when the side cannot be confirmed from the record.

Unlike the aorta, the inferior vena cava, and the mesenteric arteries, renal vessel lacerations have no minor or major split in ICD-10-CM. The depth of the tear does not change the code. Renal vein injuries that are not lacerations go to S35.40- (unspecified injury) or S35.49- (other specified injury).

Clinical recognition matters here. A report describing “renal hilar bleeding” or “kidney injury” without naming the renal vein does not support S35.416D. A laceration of the kidney itself is coded in category S37.0- (injury of kidney), not in S35.4-.

Understanding the 7th character D: Subsequent encounter

The 7th character D denotes a subsequent encounter. The patient is receiving routine care for an injury that is healing or has healed, after active treatment has concluded. Per ICD-10-CM Official Guidelines Section I.C.19, a subsequent encounter begins when the patient returns for follow-up care that is no longer part of active treatment.

Three encounter types apply across all S35.41- codes. Each maps to a specific clinical scenario:

A common misapplication: Coders switch to D on the first outpatient visit after discharge. That is wrong when the patient returns for a planned reoperation or further interventional radiology. If any active treatment is still occurring, character A remains correct regardless of the care setting.

S35.416A vs S35.416D vs S35.416S: Choosing the right encounter suffix

The treatment phase decides between A, D, and S, whatever the care setting or the number of visits. Apply this three-question logic before selecting the suffix:

1. Is the injury still receiving active treatment? Yes: Use A. No: Proceed to question 2.
2. Has the injury healed and is a residual condition now the clinical focus? Yes: Use S (code the sequela condition first). No: Proceed to question 3.
3. Is the patient returning for routine follow-up, monitoring, or supportive care for a healing injury? Yes: Use D.

Sequela coding under S is less common than coders assume. It applies only when the provider links a distinct late-effect condition to the renal vein injury, such as reduced kidney function. When both the original injury and a developing complication are active, code the injury (with A or D as appropriate) alongside the complication.

Laterality and the treatment phase work together, so the grid below sets all nine renal vein laceration codes side by side.

Codes commonly confused with S35.416D

The S35 category is dense with vessel-specific codes. Selecting the wrong one usually comes down to missing laterality, misidentifying the vessel, or using a laceration code for a different injury type. Accurate renal vascular injury coding depends on distinguishing between the following neighbors:

The practical fix: Query the surgeon or radiologist any time the report describes a renal vein laceration without naming the side. A single clarification addendum moves the claim from S35.416D to S35.414D or S35.415D.

Excludes notes and coding conventions for S35.416D

The FY2027 tabular list carries the following instructional notes that apply to S35.416D:

• Code also any associated open wound (S31.-): Category S35 carries this note. When an open wound of the abdomen, flank, or lower back accompanies the vascular injury, assign both codes.
• Use additional code for external cause (V00-Y99): The Chapter 19 note directs coders to add a Chapter 20 code to identify the cause of injury. Section I.C.20 sets no national mandate, but state reporting rules and many payers require it.
• External cause on a follow-up visit: The external cause code takes the same 7th character as the injury code. A D encounter carries a D external cause code. Place of occurrence (Y92), activity (Y93), and status (Y99) codes are reported only at the initial encounter.
• No Excludes1 note applies at the S35, S35.4, or S35.41 level. Notes at the chapter and block level still cascade down, so check them in the current tabular list.
• Sequencing: S35.416D is the principal or a secondary diagnosis depending on the reason for the encounter. In a follow-up visit focused solely on the renal vein injury, it is listed first.

Documentation requirements to support S35.416D

Five documentation elements must be present in the medical record before S35.416D can be coded. Coding from inference instead of explicit documentation is a frequent audit finding on low-volume trauma codes. For this code, medical billing compliance starts in the operative note and the follow-up record.

• Named vessel: The renal vein must be named in the operative note, radiology report, or discharge summary. “Renal vascular injury” or “renal hilar bleeding” is not enough.
• Injury type: The record must describe a laceration, such as a tear, transection, or disruption of the vein wall. If it describes another injury type, use S35.406D or S35.496D instead.
• Laterality: Check every source in the record for the side before settling on S35.416D. If any note names the right or left renal vein, use S35.414D or S35.415D.
• Encounter type: The clinical note must show that this visit is follow-up for a healing injury, not active treatment. Phrases such as “surveillance visit” or “wound check following renal vein repair” support character D.
• External cause: The mechanism of injury should be documented to support the external cause code. The injury narrative in the emergency or admission note is acceptable documentation.

According to the AAPC ICD-10-CM coding resources, coders should query providers when documentation does not support the most specific code. For S35.416D, the query almost always asks which side was injured.

Payer guidelines and medical necessity for S35.416D

No National Coverage Determination (NCD) directly addresses S35.416D. Coverage is determined at the Medicare Administrative Contractor (MAC) level through Local Coverage Determinations (LCDs) for the underlying service billed alongside the diagnosis code.

For a subsequent-encounter visit using S35.416D, the E&M or procedure code billed must be medically necessary for the stage of injury recovery. Payers look for documentation that explains why an in-person visit is needed at this point in recovery. CMS publishes the current code files and official guidelines on its ICD-10 coding guidance page.

• Prior authorization: Generally not required for the diagnosis code itself. PA requirements apply to the procedure or service billed alongside S35.416D.
• Unspecified laterality: Payers may question an unspecified-side code when the record names the side. Keep the claim consistent with the most specific documentation available.
• External cause code: Payers and states that mandate external cause reporting can reject trauma claims sent without a V00-Y99 code.
• Commercial payers: Most follow CMS coverage principles for traumatic vascular injury follow-up. Confirm payer-specific requirements through the MAC or commercial payer’s provider portal.

Why claims using S35.416D get denied, and how to fix them

S35.416D denials cluster around four root causes. Recognizing the pattern behind each denial makes the corrective path straightforward. Effective denial management workflows map each rejection reason to the specific record or claim fix it needs. Treating every denial as generic rework slows recovery.

Match the reason code on the remittance against the table above to find the fix. Our guide to medical billing denial codes explains what each reason code means. Cite the correct ICD-10-CM guideline section and attach the provider addendum in the first appeal, rather than waiting for a second denial.

How Pabau’s claims management supports S35.416D billing

Low-volume trauma codes like ICD-10 code S35.416D rarely reach a coder’s daily queue. When a code turns up only occasionally, a manual review can miss the 7th character or the external cause code that should travel with it.

Pabau’s claims management software scrubs each claim for missing or invalid details before it leaves the practice. Claims submitted electronically via Claim.MD go to thousands of US payers, and Claim.MD is Pabau’s US clearinghouse partner.

• Eligibility checks: Real-time 270/271 eligibility checks confirm the patient’s coverage before the follow-up visit.
• Electronic claims: CMS-1500 claims are built and sent electronically, so no paper form is rekeyed.
• Claim validation: Pabau’s claims management software scrubs each claim for missing or invalid details before submission.
• ERA tracking: Electronic remittance advice is tracked against each claim, so a denial shows up with its reason code.

Trauma surgery practices bill the S35 category more often than most. For them, pairing the encounter logic above with a clean claim checklist covers every S35.41- code before it goes out.

Catch claim errors before they reach the payer

Pabau’s claims management and Claim.MD clearinghouse connection scrub each claim for missing or invalid details before submission. Your team spends less time on appeals and more time on patient care.

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Conclusion

Treat every S35.416D as a prompt to read the chart once more. If any note names the side, S35.414D or S35.415D is the stronger claim, and one provider query usually settles it. If active treatment is still under way, the visit belongs on S35.416A instead.

Practices handling abdominal trauma billing can reduce S35.416D denials structurally by scrubbing claims for missing or invalid details before submission. Tracking electronic remittance advice against each claim then shows whether a corrected code was paid. Book a demo to see how Pabau scrubs, submits, and tracks trauma follow-up claims in one workflow.

Continue your research

Want a structured approach to appeal S35.416D denials? Medical billing denial codes covers CARC/RARC code interpretations and the appeal documentation your team needs.

Is the kidney itself lacerated too? ICD-10 code S37.049D covers a minor laceration of an unspecified kidney at a follow-up encounter.

Does the report describe bleeding at the vena cava? ICD-10 code S35.10XD covers an unspecified injury of the inferior vena cava at a follow-up encounter.

Coding a laceration of a different abdominal vein? ICD-10 code S35.311D covers a laceration of the portal vein at a follow-up encounter.

Need the main code sets on one page? Medical coding cheat sheet puts CPT, ICD-10, HCPCS, and E/M codes in one printable reference.

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