ICD-10 code S43.491S: Other sprain of right shoulder joint, sequela

Key takeaways

ICD-10 code S43.491S covers other sprain of right shoulder joint, sequela, and it is billable for FY2026.

The 7th character S means the visit treats a late effect of the original sprain, not the active injury.

Sequela coding needs a documented link between the current shoulder problem and the earlier sprain.

Missing that causal statement is a common audit finding on sequela claims.

Practice management software like Pabau keeps sequela documentation and claims data in one patient record.

ICD-10 code S43.491S is a billable, specific ICD-10-CM diagnosis code. It covers other sprain of the right shoulder joint when the visit treats a sequela of that injury. No more granular code is required on the claim.

The code sits in the S43.4 subgroup for sprain of the shoulder joint, and it is specific to the right side. Documentation has to name the right shoulder and show that the visit treats a sequela rather than an active injury. Practices working from structured clinical records can flag sequela visits at the point of care, before a 7th-character error reaches the claim.

Understanding the 7th character ‘S’: Sequela explained

The 7th character is the most consequential position in a traumatic injury code. Chapter 19 codes offer three options in that slot: A for initial encounter, D for subsequent encounter, and S for sequela. Payers read the character to judge whether the care billed matches the stage of the injury.

Sequela describes a condition that arises as a direct result of an earlier injury. That is the definition used in the CMS ICD-10-CM guidelines. The sequela code belongs on the visit that treats the late effect, not on the injury itself.

• Initial encounter (A): The patient is in active treatment for the injury. Surgical and non-surgical care during the acute phase both count.
• Subsequent encounter (D): The injury is still healing. The patient is in routine follow-up, physical therapy, or cast management.
• Sequela (S): The original injury has resolved or stabilized, but a residual condition persists as a direct consequence.

Coders trip most often on the line between subsequent encounter and sequela. A patient who returns three weeks later with a shoulder that is still healing is a subsequent encounter, so D applies.

Sequela applies once the sprain is considered resolved and the patient still has stiffness, pain, or lost function caused by it. Chart notes should make that distinction explicit.

S43.491A vs S43.491D vs S43.491S: Choosing the right encounter code

All three variants of S43.491 are billable. What separates them is the episode of care, not the severity of the injury or the procedure performed.

Sequencing matters once you reach for S43.491S. Section I.C.19.a of the ICD-10-CM guidelines puts the nature of the sequela first. A code such as M25.511 for pain in the right shoulder leads the claim. S43.491S follows it and establishes the link back to the original injury.

Practices that also code fracture aftercare will recognize the pattern from codes like S42.409P, where the 7th character carries the whole story. Keeping that order consistent across the record saves the coder a second reading.

Code hierarchy: Where S43.491S fits in ICD-10-CM

Checking the parent structure confirms you have landed at the right level of specificity. S43.491S is a leaf-level code, so no further subdivision exists and it satisfies the billable-code requirement.

• S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (Chapter 19)
• S40-S49 — Injuries to the shoulder and upper arm
• S43 — Dislocation and sprain of joints and ligaments of shoulder girdle
• S43.4 — Sprain of shoulder joint
• S43.49 — Other sprain of shoulder joint
• S43.491 — Other sprain of right shoulder joint
• S43.491S — Other sprain of right shoulder joint, sequela (billable)

The other sprain label at the S43.491 level covers sprains that do not map to a more specific S43.4x code. An acromioclavicular sprain, for example, has its own subcategory.

If the note names the ligament or joint structure involved and a more specific code exists, use the specific one. The CDC ICD-10-CM tool shows the full tabular view for that check.

Our roundup of alternatives to Jane App looks at platforms that pair injury coding with rehab treatment plans.

Clinical scenarios: When to use ICD-10 code S43.491S

Three things have to be in the chart before you assign S43.491S. The patient had a prior right shoulder sprain. That injury has resolved, or it is no longer being actively treated. The current problem is a direct consequence of it.

Common presentations where S43.491S applies include:

• Persistent right shoulder pain or stiffness after a fully resolved acute sprain
• Post-traumatic adhesive capsulitis that developed after a prior shoulder ligament injury
• Reduced range of motion documented as a late effect of the sprain rather than a new injury
• Physical therapy referrals for chronic functional limits caused by the earlier sprain
• Pain management visits where the clinician links today’s pain to the documented sprain

Sports medicine and orthopedic practices see this pattern in returning athletes. A player is treated through the acute and recovery phases, then comes back months later with residual weakness or pain. That final visit is a sequela encounter.

Workers’ compensation and legal claims

Workers’ compensation billing layers its own requirements on top of the coding rules. In occupational injury cases, sequela codes come up long after the original injury. A worker returns to a claims-adjusted physician with residual shoulder pain or disability.

Jurisdictional rules vary. Some states want the original injury claim number on sequela claims. Others want the primary treating physician’s records appended.

One requirement is universal: The record must document the causal chain from the occupational injury to the current condition. A note that reads only shoulder pain, history of sprain will not clear most workers’ comp payers.

For practices carrying high volumes of occupational injury cases, note templates that prompt for the causal statement are worth the setup time. Denials cluster where that language is missing.

Associated CPT codes for right shoulder sprain sequela

S43.491S is a diagnosis code, not a procedure code. It has to be paired with the CPT codes that describe what was done at the visit. The codes below appear most often on sequela shoulder sprain claims.

Payer policy decides which of them count as medically necessary for this diagnosis. Local Coverage Determinations (LCDs) and National Coverage Determinations (NCDs) set those limits, so confirm the pairing with each payer before you submit.

Practices billing physical therapy codes alongside S43.491S should check that their claims management software applies the right diagnosis-to-procedure pairings. Payers sometimes query a sequela code sitting next to acute-phase CPT codes.

A therapy evaluation such as 97161 can trigger a records request, to confirm the visit treats a late effect rather than an ongoing acute injury. The AAPC code lookup lists the coding notes and associated procedure codes attached to S43.491S.

Related ICD-10 codes for shoulder sprains and injuries

S43.491S belongs to a wider family of shoulder sprain codes. Knowing the neighbors helps you pick the most specific option, instead of defaulting to other sprain. The table covers the codes referenced most often in the S43.4x range.

Laterality errors account for a large share of shoulder code rejections, so confirm right or left from the note before you assign. The WHO ICD-10 browser gives a hierarchical view of the full S43 block for cross-referencing.

Anyone opening a new physical therapy practice should build laterality confirmation into intake and documentation from day one. Retrofitting it across a year of charts is far more work.

Differential diagnosis: Distinguishing S43.491S from similar codes

Several ICD-10-CM codes describe right shoulder conditions that overlap with sequela sprain presentations. Picking the wrong one creates a mismatch between the claim and the medical record, even with the right 7th character.

• M75.100: Unspecified rotator cuff tear or rupture of unspecified shoulder, not specified as traumatic. Use it when the note identifies rotator cuff pathology as the primary diagnosis. Where the cuff problem is a direct result of the prior sprain, S43.421S fits better, with M75.100 as a secondary code. A confirmed complete tear on the right side is coded M75.121.
• M79.621 (Pain in right upper arm): A symptom code. Once the cause is identified as a sequela of a prior right shoulder sprain, S43.491S leads and the symptom code does not.
• M75.30 (Calcific tendinitis, unspecified shoulder): A separate pathology. Calcific tendinitis is not coded as a sequela of a sprain unless the chart explicitly establishes causation.
• M53.1 (Cervicobrachial syndrome): Cervical origin rather than shoulder joint. When the presentation looks like shoulder sprain sequela but the pain radiates from the cervical spine, this code applies instead.

The documented causal statement is the clearest differentiator. M-chapter codes describe chronic or degenerative conditions. Chapter 19 codes carrying an S describe conditions that arise from a prior injury.

Where the chart documents causation from the original sprain, the Chapter 19 sequela code takes precedence. Defining that split inside your clinical note templates removes most of the ambiguity at coding time.

Related ICD-10 codes

• ICD-10-CM code S39.012A — Lumbosacral Strain Initial Encounter
• ICD-10 code S45.019A — Laceration of axillary artery, unspecified side
• ICD-10 code S48.922S — Partial left shoulder amputation – sequela
• ICD-10 code S49.029P — Salter-Harris II malunion, unspecified arm

How Pabau supports sequela documentation and clean claims

In most practices, the missing causal statement surfaces after the denial arrives. The coder reads the note, cannot find the link back to the original sprain, and emails the clinician for an addendum. That round trip holds the claim for days.

Practice management software like Pabau moves the prompt to the point of care. Pabau Scribe.

The result is a chart that answers the payer’s question before it is asked. Coders see the causal statement in the note, claims leave with matched diagnosis and procedure codes, and fewer visits come back for records review.

Reduce coding errors before claims leave your practice

Pabau’s clinical documentation and claims tools build sequela evidence into every encounter. Coders get what they need without chasing clinicians for addenda.

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Conclusion

Sequela coding rewards the practice that writes the causal sentence once, at the point of care. S43.491S itself is simple. The record around it decides whether the claim gets paid.

The trade-off is worth remembering. You either spend the effort in the note template now, or in addenda and appeals later. Practices that choose the template see fewer denials and shorter payment cycles.

Book a demo to see how Pabau keeps sequela documentation and claims in step for physical therapy, sports medicine, and orthopedic practices.

Continue your research

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Ruling out a cervical cause first? The cervical rotation lateral flexion test separates neck-driven shoulder pain from joint pathology, with a scored procedure.

Coding fractures on the same caseload? S52.355J shows how much the 7th character has to carry on a fracture claim.

Standardizing functional testing in rehab? The lateral step down test shows how a scored movement test gets documented so the findings hold up later.

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