ICD code V46.1XXS – Car passenger injured in nonmotor vehicle collision

Key takeaways

V46.1XXS covers a car passenger, not the driver, injured in a nontraffic collision with another nonmotor vehicle. That means a streetcar, an animal-drawn vehicle, or an animal being ridden.

Do not confuse V46 with V44, which covers collisions with a heavy transport vehicle or bus. Mixing the two is the most common error on this code.

The 7th character ‘S’ marks a sequela encounter, where the visit treats a late effect of the injury rather than the injury itself.

This is an external cause code from the V00-Y99 chapter, so it cannot stand alone as the principal diagnosis. It must accompany a primary nature-of-injury code.

Pabau’s claims management software validates billable status and links external cause codes to primary injury codes before submission, reducing sequela-related denials.

ICD-10 code V46.1XXS: Definition and code attributes

ICD-10 code V46.1XXS is a valid, billable ICD-10-CM code in the fiscal year 2026 edition, which took effect on October 1, 2025. Its full official descriptor is: Car passenger injured in collision with other nonmotor vehicle in nontraffic accident, sequela.

The code belongs to the V00-Y99 external cause of morbidity chapter. That placement means it supplements a primary injury code rather than replacing it.

The phrase “other nonmotor vehicle” is defined by the inclusion note under V46. It covers a streetcar, an animal-drawn vehicle, and an animal being ridden. A collision with a truck or a bus is coded to V44 instead. A collision with another car, a pick-up truck, or a van belongs to V43.

Because V46.1XXS lives in the external cause chapter, it cannot appear as a standalone claim. The CMS ICD-10-CM coding resources make clear that external cause codes are always secondary to the nature-of-injury code.

Common primary codes here include S13.4XXS for cervical sprain sequela and S14.2XXS for injury of a cervical nerve root, sequela. A cervical spinal cord injury is coded to S14.0 or S14.1 instead, never to S14.2.

What the 7th character “S” means for sequela encounters

The 7th character in ICD-10-CM injury codes indicates the type of encounter. Choosing the wrong one is a frequent reason sequela claims are denied. For the V46.1 code family, three extensions apply.

Per the CDC/NCHS ICD-10-CM official tool and Section I.C.19 of the annual guidelines, the “S” extension carries two conditions. The original injury must have reached maximum medical improvement.

The current visit must be for a residual or late-effect condition traceable to that injury. Common sequelae after these collisions include chronic cervical pain, peripheral neuropathy, PTSD, and post-traumatic arthropathy.

Sequela vs. subsequent encounter: A side-by-side comparison

Both D and S apply after the first visit, which is where the two get swapped. A subsequent encounter (D) is used while the patient is still under active treatment for the injury. A sequela encounter (S) is used once the injury itself has resolved and the patient is dealing with a downstream condition it caused.

What is a nontraffic accident in ICD-10 coding?

A nontraffic accident is any transport accident that does not occur on a public roadway open to normal motor vehicle traffic. The distinction is codified in the ICD-10-CM official guidelines. For an injured car passenger it decides between V46.1 (nontraffic) and V46.6 (traffic).

• Qualifies as nontraffic: parking lots, private driveways, agricultural fields, construction sites, factory yards, loading docks, racetracks closed to public traffic
• Does NOT qualify as nontraffic: any public road, highway, street, or intersection open to general vehicle use, even at low traffic volume
• Ambiguous scenarios: shopping center parking lots are typically treated as nontraffic. An unpaved forest road open to the public may qualify as traffic, depending on local jurisdiction and documentation

The nontraffic qualifier in V46.1 is meaningful because it shifts liability context and affects how insurers review claims. If the accident occurred on a public road, V46.6 (traffic accident) codes are required. Using V46.1XXS for a public-road collision is a coding error that can result in claim rejection or audit flags.

V46 code category: Car occupants injured in collision with other nonmotor vehicles

The V46 category covers every car occupant position injured in a collision with another nonmotor vehicle. The inclusion note names a streetcar, an animal-drawn vehicle, and an animal being ridden. Knowing where V46.1XXS sits in that hierarchy prevents the most common category-level errors.

The placeholder “X” characters in positions 5 and 6 are required by ICD-10-CM convention. When a code has fewer than 6 characters before the 7th character extension, the empty positions must be filled with “X.” Submitting V46.1S without the placeholders will be rejected as an invalid code.

ICD-10-CM coding guidelines for injury sequela

The ICD-10-CM official guidelines, Section I.C.19, govern how sequela codes for injuries are applied. For injury external cause codes the rule is consistent. Report the sequela code for the nature of the injury together with the external cause sequela code.

1. Confirm injury resolution: The original collision trauma must be fully resolved before the “S” extension is used. Active fractures, open wounds, or acute inflammation still require the “D” subsequent encounter extension.
2. Identify the residual condition: Code it as the principal diagnosis using the appropriate injury code with the “S” extension. A sequela cervical sprain code is one example.
3. Add the external cause code: V46.1XXS follows the primary sequela injury code as a secondary code. It identifies the cause of the original injury and the encounter type.
4. Document the causal link: The physician note must explicitly connect the current residual condition to the original nontraffic collision. A note reading “chronic neck pain secondary to a horse-drawn carriage collision in a private yard six months ago” is acceptable. “Neck pain” with no mention of the original event is not.
5. No time limit on sequela coding: No statutory time limit governs how long after an injury sequela coding may apply. Years after a nontraffic collision, a patient presenting with collision-related neuropathy may still be coded with V46.1XXS.

Many clearinghouses flag claims where the sequela injury code and the external cause code carry mismatched 7th characters. Both must carry “S.”

Clinical scenarios: When to use ICD-10 code V46.1XXS

ICD-10 code V46.1XXS applies to a narrow clinical situation, and four decisions get you there. The injured person was a car passenger, not the driver and not someone on the outside of the car.

The car collided with another nonmotor vehicle. The accident happened off a public roadway, and the current visit treats a late-effect condition.

The scenarios below show correct and incorrect application.

• Correct use: A patient was a rear-seat passenger in a car struck by a horse-drawn carriage on a private estate road eight months ago. The acute soft-tissue injuries have resolved. She presents today with persistent bilateral hand numbness that the neurologist attributes to cervical nerve root damage from the collision. Principal diagnosis: S14.2XXS. Secondary: V46.1XXS.
• Correct use: A transit depot worker was riding as a passenger when a streetcar struck the car inside a closed tram yard. He presents two years later with PTSD that his psychiatrist attributes directly to the accident. The psychiatric diagnosis carries the principal sequela code, and V46.1XXS is secondary.
• Incorrect use: Same accident, but the patient’s cervical fracture is still under active healing with a brace in place. That makes it a subsequent encounter (D) rather than a sequela (S).
• Incorrect use: The collision with the animal-drawn vehicle occurred on a public highway. V46.6XXS (passenger, traffic, sequela) is the correct code. V46.1XXS would misrepresent the accident location.
• Incorrect use: The car was struck by a delivery truck in a private loading yard. A heavy transport vehicle sits in category V44, so V44.1XXS applies instead of V46.1XXS.

Post-traumatic psychiatric conditions such as PTSD, adjustment disorder, and anxiety are among the more common sequelae after a motor vehicle accident. Each one carries its own primary sequela code alongside V46.1XXS.

Documentation requirements for V46.1XXS

Sequela claims are audited more rigorously than initial or subsequent encounter claims. Months or years separate the original injury from the current visit, which leaves the causal chain open to question. Payers look for that chain in writing. For clean claim submission, the physician note supporting V46.1XXS must contain all of the following.

• Description of the original injury event: date, location (confirming nontraffic), and occupant position (passenger, not driver). Name the other vehicle too: a streetcar, an animal-drawn vehicle, or an animal being ridden.
• Statement of injury resolution: explicit documentation that the acute injury has resolved or reached maximum medical improvement. “The original cervical sprain has resolved” is sufficient; an ambiguous note that could be read as ongoing acute care is not.
• Identification of the residual condition: the specific late-effect condition treated at this visit. Link it with language such as “secondary to,” “as a result of,” or “sequela of.”
• Causal connection: the note must assert a direct clinical relationship between the original nontraffic collision and the current residual condition. A specialist letter or prior treating provider note referenced in the record can support this where the current provider did not treat the acute phase.

A note that documents the residual condition without mentioning the original accident gives a payer grounds to deny on medical necessity. Those denials come back under the same denial codes that cover any other documentation failure. Track them as a group rather than case by case.

Adjacent and related ICD-10 codes

The codes most commonly confused with V46.1XXS, or required alongside it, are listed below. After a motor vehicle accident a traumatic brain injury sequela code often carries the principal diagnosis, with V46.1XXS as the secondary external cause code.

Practices submitting these paired combinations can validate the pairing logic inside an integrated billing platform before the claim leaves the practice. Remittance responses then land against the same claim record, so patterns in sequela outcomes surface faster.

ICD-9-CM crosswalk for V46.1XXS

For practices working with legacy data or historical claim research, the closest ICD-9-CM equivalents to V46.1XXS are shown below.

The General Equivalence Mappings (GEMs) published by CMS do not produce a one-to-one match. ICD-9 lacked the 7th character encounter-type system, and it classified these accidents by the nonmotor vehicle involved rather than by the car occupant’s position.

The fourth digit in the E826-E829 range identifies the injured person rather than the car occupant position. None of these codes reproduces the driver, passenger, and outside-the-car split that V46 makes. ICD-9 also had no equivalent to the sequela 7th character. Late effects were coded with separate late-effect categories, the E929.x series.

For crosswalk purposes, ResDAC guidance on ICD codes in Medicare files treats GEM mappings from external cause codes as approximate. Have a certified coder review them before using them in retrospective research or billing. Crosswalk codes serve historical analysis only, and ICD-9 codes cannot be submitted on current claims.

Submitting V46.1XXS claims: Clearinghouse and billing workflow

V46.1XXS is an external cause code in the supplementary range, so it will never appear as the first-listed code on a claim. Most US payers accept external cause codes as secondary diagnosis codes on the CMS-1500 form and 837P electronic claims.

Some commercial payers and Medicaid programs designate them as optional rather than required. Confirm payer-specific requirements before assuming they are always needed.

Pabau submits through Claim.MD, our US clearinghouse partner, which reaches thousands of US payers and validates ICD-10-CM code pairings before transmission. That check catches a mismatched 7th character before the claim reaches the payer.

One example is a principal injury code carrying “D” alongside an external cause code carrying “S.” The ERA/835 remittance data is stored against the claim, so denial patterns for sequela pairings can be tracked over time.

How Pabau keeps external cause code pairings clean

Coding a sequela claim by hand means holding two codes at once. The coder looks up the nature-of-injury code, checks its 7th character, then finds the matching external cause code in a separate reference. The patient record itself offers no confirmation that the two agree, so the mismatch surfaces when the payer rejects the claim.

Pabau, practice management software for medical and aesthetic practices, moves that lookup into the encounter. Coders attach V46.1XXS and its paired injury code from inside the patient record. The billing software for practices then flags a 7th-character mismatch before anything is transmitted.

The documentation that supports the claim stays with the record too. The original accident note, the statement of resolution, and the causal link sit in one patient file. An audit request is answered from that file instead of a search across three systems.

Stop switching tabs to look up ICD-10 codes

Pabau embeds ICD-10-CM code lookup directly in the clinical encounter. Attach V46.1XXS and its paired injury code to a claim without leaving the patient record, then submit it to the clearinghouse in the same workflow.

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Conclusion

V46.1XXS is a narrow code, and both decisions that put a claim at risk are decisions about documentation. The first is applying it during active treatment, when the D extension is correct. The second is using it for a collision on a public road, where V46.6XXS applies.

Read the accident note before you pick the 7th character, and query the provider whenever the location or the injury status is unclear. A note that names the place, the occupant position, and the resolution of the original injury will carry the claim on its own.

Pabau surfaces ICD-10-CM code attributes, validates code pairings, and submits to the clearinghouse in a single workflow. Book a demo to see how external cause sequela claims move through it.

Continue your research

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