ICD-10 code S43.312S: Subluxation of left scapula, sequela

Key takeaways

ICD-10 code S43.312S is a billable code for subluxation of the left scapula, sequela, valid for the 2026 ICD-10-CM edition.

The 7th character S means you are treating what the old injury left behind, not the injury itself.

Code the residual condition first and S43.312S second, and give the original injury a date in the note.

The note has to say left and has to say subluxation, because dislocation of the left scapula, sequela is S43.315S.

Practice management software like Pabau pre-fills codes from the client record and offers ICD-10 and CPT lookup libraries, so coders work from one source.

A patient rolls their left shoulder, winces, and mentions a fall from two years ago. That injury healed long ago. The problem it left behind did not. That visit is what ICD-10 code S43.312S was written for: subluxation of the left scapula, sequela.

Typing the code is easy. Supporting it is the harder part. Payers push back when the note skips the side, blurs subluxation into dislocation, or never links today’s symptoms to the old injury. Get those three details onto the page and the claim usually clears first time.

What ICD-10 code S43.312S means

ICD-10 code S43.312S is a billable ICD-10-CM diagnosis code for subluxation of the left scapula, sequela. Report it when you treat a condition that grew out of an earlier left scapula subluxation. The code took effect on October 1, 2025 with the 2026 ICD-10-CM edition maintained by CMS.

The string carries two facts at once. Its first six characters name the injury and the side. That final S says the injury has already run its course, and you are treating what it left behind.

The code at a glance

Confirm billable status, the parent category, and the effective date before the claim goes out.

The 7th character S puts the visit after the injury

The 7th character tells the payer which stage of care the visit belongs to. Three values are valid for S43.312, and each one describes a different episode. Choose the wrong one and the claim describes care the patient never had.

How to sequence a sequela claim

Code the residual condition first, then S43.312S. The ICD-10-CM Official Guidelines (Section I.C.19) put the sequela condition in the first position.

Behind it sits the injury code carrying that S character. So chronic left shoulder pain leads, and S43.312S shows the reviewer where that pain came from.

Other sequela codes across the injury chapter work the same way, including S70.259S. Time is not a factor either. A subluxation from 2019 still supports S43.312S today, as long as the record traces the current condition back to it.

What a left scapula subluxation looks like in the chart

Subluxation means the joint surfaces have slipped out of alignment but still touch. A dislocation separates them completely.

The scapula, or shoulder blade, sits at the back of the shoulder girdle and meets the clavicle at the acromioclavicular joint and the humerus at the glenohumeral joint.

Most cases follow trauma to the shoulder, repeated overhead work, or a neuromuscular problem in the muscles that stabilize the scapula.

Typical findings in the note include:

• Localized pain at the back of the shoulder or upper back
• Reduced range of motion on the left side
• Clicking or grinding with arm movement
• Visible winging of the scapula in some cases
• Weakness when reaching or pushing overhead

Subluxation and dislocation both live under S43.31

There is no separate dislocation block for the scapula. Both injuries share the subcategory S43.31, and the fifth digit is what splits them.

Subluxation runs from S43.311 to S43.313. Dislocation runs from S43.314 to S43.316. The dislocation counterpart of S43.312S is therefore S43.315S.

Where S43.312S sits in the ICD-10 hierarchy

Walking the hierarchy is the quickest way to prove you have the most specific code available. The CDC ICD-10-CM tool shows the same path in the tabular list.

• Chapter 19: Injury, poisoning and certain other consequences of external causes (S00-T88)
• Block S40-S49: Injuries to the shoulder and upper arm
• Category S43: Dislocation and sprain of joints and ligaments of shoulder girdle
• Subcategory S43.3: Subluxation and dislocation of other and unspecified parts of shoulder girdle
• Subcategory S43.31: Subluxation and dislocation of scapula
• Code S43.312: Subluxation of left scapula
• Code S43.312S: Subluxation of left scapula, sequela

S43.312S is a leaf code, so nothing sits below it and no extra digit is available. It can stand as the primary diagnosis on a claim. Check the Includes and Excludes1 notes in the tabular list before you finalize, since S43 borders several sprain categories.

Teams running a physical therapy EMR with the hierarchy built into code lookup skip most of that manual checking.

Check the sibling codes before you commit

The scapula subluxation family is symmetrical: right, left, and unspecified, each with its own 7th character.

Bilateral injuries and undocumented laterality need one of the siblings below rather than a default to S43.312S. The AAPC ICD-10-CM code reference lists each one with its billable status.

Nearby shoulder girdle codes follow the same 7th-character pattern, so S43.121S reads the same way once you know the structure. Fracture categories go further and add characters for malunion and nonunion, as S49.109P does with P.

Documentation that holds up for S43.312S

Three things have to be on the page: the side, the word subluxation, and a stated link to the original injury. Miss one and the claim invites a denial or an audit flag.

Structured client record management gives the team one place to capture all three at every visit.

• Name the side in words. „Shoulder subluxation“ with no laterality supports S43.313x, not S43.312S.
• Say subluxation, not dislocation. Imaging, exam findings, or a specialist letter should record partial displacement rather than full separation.
• Tie today’s problem to the old injury. Give the date, or at least the month and year, of the original subluxation.
• Code the residual condition too. Chronic pain or restricted motion needs its own code alongside S43.312S.

Retention rules apply to all of it. The same medical office compliance standards that govern storage also set how long these injury records stay on file.

How an S43.312S claim moves from visit to payment

The claim travels the usual route, with one extra link in the chain. First, the clinician documents the visit and names the residual condition as the primary diagnosis. S43.312S goes on the claim behind it.

Billing then adds the procedure or therapy codes for the work performed, whether that was manual therapy or an injection such as CPT 20550.

Two automated checks happen before a human reads anything. The payer’s software confirms the 7th character is valid, then tests the diagnosis against the procedure billed.

Sequela claims usually stumble at the second check, because a therapy code needs a residual condition to justify it. Practices that bill by hand hit the same wall on the superbill template they hand to patients.

Run these five checks before you submit

• The note names the left side in words, not only in an image label.
• The record says subluxation, rather than dislocation or „shoulder injury“.
• The residual condition sits in the first diagnosis position.
• The original injury carries a date, or at least a month and year.
• The procedure and therapy codes match the residual condition you listed.

Where these claims usually go wrong

• Reporting S43.312S at the first visit for a fresh injury, when that encounter takes S43.312A.
• Sending S43.312S on its own, with no residual condition code beside it.
• Defaulting to S43.313S because a template’s laterality field was left blank.
• Copying the sequela code forward after the patient re-injures the same shoulder.

When S43.312S fits, and when it does not

Five short cases mark the boundary. Three call for S43.312S. Two call for a different 7th character.

• Correct: A patient subluxated the left scapula in a fall six months ago. The acute episode healed, and they now report chronic posterior shoulder pain with reduced abduction. Code the chronic pain, then S43.312S.
• Correct: A former collegiate swimmer attends therapy for glenohumeral instability traced to a left scapular subluxation two years ago. S43.312S shows where the instability began.
• Correct: Scapular winging and periscapular weakness develop after last year’s workplace shoulder injury. The record confirms partial subluxation at the time, so S43.312S applies.
• Incorrect: A patient arrives at the emergency department with an acute left scapula subluxation today. That is an initial encounter, so use S43.312A.
• Incorrect: A patient attends follow-up while the original subluxation is still healing. Use S43.312D for the subsequent encounter.

Volume is what turns these judgment calls into a workflow problem. Practices seeing shoulder sequelae every week need prompts at the point of care.

That is where sports medicine software with built-in code lookup earns its keep. Catching the encounter type in the room beats fixing it during month-end reconciliation.

Is S43.312S still valid for 2026?

Yes. S43.312S is valid for the 2026 ICD-10-CM edition and took effect on October 1, 2025. No description change, deletion, or category revision touched this code for FY2026. The scapula subluxation subcategory reads exactly as it did the year before.

Still, check validity each October before the first claims go out. Payers adjudicate against the edition in force, so a retired code is rejected no matter how well the visit was documented. Annual code set updates handled by your software remove that audit from the to-do list entirely.

How Pabau keeps sequela coding and claims in step

Coding knowledge often lives in one person’s head. That coder reads the note, opens a lookup in another tab, and types the string into the claim by hand. Every hop invites a dropped laterality digit or the wrong 7th character.

Practice management software like Pabau keeps that chain in one place. Diagnosis and procedure codes come off the client record and onto the invoice and claim, so nobody retypes them. ICD-10 and CPT lookup libraries sit in the same screen the coder already has open.

From there, claims management software tracks what went out and what came back. A denied sequela claim surfaces in days instead of at month end.

The clinical judgment stays with your clinician and coder, which is exactly where it belongs. Pabau simply stops the code they chose from changing on its way to the payer.

Keep ICD-10 coding and claims in one place

Pabau pulls diagnosis and procedure codes from the client record and keeps ICD-10 and CPT lookup libraries in reach. Your team codes from the note in front of them, not from a second system.

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Conclusion

S43.312S has a strict story to tell. The injury healed, and something it left behind is being treated today. When the note carries a side, a date, and the word subluxation, the code does that job quietly.

So build the check into the visit rather than into the appeal. A coder who confirms laterality and sequencing before submission rarely meets this code twice.

Want that check to live inside your own workflow? Book a demo and see how Pabau keeps records, coding, and claims moving together for physical therapy and sports medicine practices.

Continue your research

Coding a shoulder muscle or tendon injury instead? S46.191A walks through the initial encounter rules for soft tissue injuries around the shoulder.

Need a 7th character that carries two facts at once? S72.036E shows how one character can signal both the encounter and the healing status.

Billing another sequela of an old fracture? S72.124S applies the same two-code sequencing rule to the hip and thigh block.

Billing electrical stimulation during shoulder rehab? G0283 covers the Medicare rules for unattended stimulation in a therapy plan of care.

Need to record residual function over time? The functional status questionnaire gives a repeatable way to show deficits that justify continued care.

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