ICD-10 code S76.129S: Laceration of quadriceps muscle sequela

Key takeaways

S76.129S is a billable ICD-10-CM code for laceration of unspecified quadriceps muscle, fascia and tendon, sequela, valid for the 2026 edition.

The 7th character ‘S’ designates sequela. It means the patient presents with a residual condition left by an earlier quadriceps laceration, not an active injury.

A common coding error is applying S76.129S during active treatment. Use S76.129A for the initial encounter or S76.129D while the injury is still being treated.

The record must show the prior laceration, its healed status, and the residual condition being treated.

Practice management software like Pabau keeps the original injury note and the current rehab visit in one patient record. That is what a sequela claim needs.

S76.129S is the billable ICD-10-CM code for laceration of unspecified quadriceps muscle, fascia and tendon, sequela. It applies after the original laceration has healed, when the patient is treated for what that injury left behind. The code is valid for the 2026 edition and can be submitted for reimbursement.

The table below summarizes the code’s key data points.

What does the ‘S’ suffix mean?

The 7th character in ICD-10-CM injury codes carries clinical meaning. It tells the payer whether the claim covers a new injury, ongoing treatment, or a late effect. Codes under the S76 category use three options: A, D, and S. Getting it wrong triggers denials and can flag the claim for audit.

The ‘S’ suffix signals that the original laceration has resolved. The patient is now seeking care for a condition caused by that prior injury. According to the WHO ICD-10 classification, sequela codes apply when treatment is directed at the late effect rather than the original injury.

The same A, D, and S ladder runs through other injury chapters, including nerve injury codes such as S64.31XS. Before submitting, coders can confirm current-edition validity with the AAPC code lookup.

Clinical description: Laceration of the quadriceps muscle, fascia and tendon

The quadriceps femoris is a group of four muscles on the anterior thigh that together extend the knee. Those muscles are the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. A laceration here may involve the muscle belly, the surrounding fascia, or the distal tendon. That tendon inserts at the tibial tuberosity through the patellar ligament.

“Unspecified” in S76.129S means laterality was not documented or is unknown. Practices running sports medicine software should record limb laterality in the clinical note whenever possible. Unspecified codes are valid for submission, but they attract more scrutiny in payer audits than S76.121S or S76.122S.

• Structures involved: Muscle belly, surrounding fascia, quadriceps tendon
• Anatomical site: Anterior thigh at the hip and thigh level, within the S76 category
• Excludes: Injuries at the lower leg level, which fall under S86
• Laterality: Unspecified, so left and right are not differentiated
• Clinical context: Sequela only, used once the laceration has healed and residual effects persist

Code hierarchy and structure for S76 injury codes

S76.129S sits at the fifth level of the ICD-10-CM hierarchy. Knowing that hierarchy helps coders pick the most specific code available and avoid upcoding or undercoding. The descent from category to billable code is below.

The S76 category excludes injuries of muscle and tendon at the lower leg level, which fall under S86. Verify the anatomical site in the clinical note before assigning any S76 code. Other injury categories follow the same pattern, including femur fracture codes such as S72.411S, where specificity increases at every level.

Includes, excludes, and applicable to notes

ICD-10-CM instructional notes at the category level apply to every code within S76, including S76.129S. The notes define the scope of the category and prevent misassignment.

• Applicable to: Injuries of muscle, fascia and tendon at hip and thigh level, covering the quadriceps, hamstrings, adductors, and hip flexors by subcategory
• Excludes1 (cannot be coded together): Injury of muscle and tendon at lower leg level (S86)
• Excludes2 (may be coded together if both conditions exist): None applicable at the S76.129S level per the 2026 tabular list
• Note: S76 codes need a 7th character for every billable submission. S76.129 on its own is not valid for a claim.

These instructional notes come from the ICD-10-CM Official Guidelines for Coding and Reporting, which CMS and NCHS maintain annually. Check the current-year tabular list before submission, because applicability notes change with each October update. Our medical coding cheat sheet collects the conventions coders reach for most often.

Related and sibling codes for quadriceps injury

S76.129S is one of three billable 7th-character extensions under S76.129. Coders also need the laterality-specific siblings under S76.12 and the other S76.1 laceration codes to pick the most accurate option.

When laterality is documented, prefer S76.121S or S76.122S over S76.129S. The unspecified code is for cases where laterality cannot be determined from the documentation. Review the full S76.1 subcategory to confirm the injury type matches. Laceration codes (S76.12x) are distinct from strain codes (S76.11x) and other injury types (S76.19x).

The quadriceps mechanism also involves the patella, and patella fracture codes such as S82.036S carry a longer list of 7th characters. Fracture codes track healing status as well as encounter phase, so the sequela character is only one option among many.

Documentation requirements for S76.129S

Sequela codes need a different documentation trail from active injury encounters. For S76.129S to hold up on audit, the record has to establish three things. Practices on a physical therapy EMR get structured templates that carry this information across encounters.

• Prior injury documentation: The record must show that the patient previously sustained a laceration of the quadriceps muscle, fascia, or tendon. A prior encounter note, operative report, or ED record all qualify.
• Healed or resolved status: The note should state that the original wound has healed. This is what separates sequela from ongoing active treatment under S76.129D.
• Current residual condition: Document the specific late effect being addressed. Chronic pain, muscle weakness, restricted range of motion, scar tissue, and adhesions are the common ones.
• Treatment rationale: The plan of care should explain why the patient is being treated now, tied directly to the sequela of the prior laceration.

Structured patient record documentation that ties today’s visit note to the original injury encounter is what makes sequela coding defensible.

A patient working through a return-to-running protocol after a healed thigh laceration is a good example. Document the functional deficits under rehabilitation and their causal link to the prior injury. The safer clinical notes guide covers note-writing patterns that support this.

When to use S76.129S vs S76.129A and S76.129D

The choice between A, D, and S is the most error-prone decision coders face with S76.129S. Each character marks a different phase of the injury episode. Picking the wrong one creates a medical necessity mismatch and exposes the practice to denial or audit.

Sequela applies when treatment addresses the consequence of the prior injury rather than the injury itself. If a provider is still treating the wound, the debridement, or the surgical repair, the encounter is not sequela. The CMS guidelines put routine follow-up and ongoing active care under ‘D’, so ‘S’ is reserved for the late effect.

Coding tips and common errors with S76.129S

Three coding errors appear repeatedly in audits of S76.129S claims. Each has a straightforward fix.

• Using ‘S’ during active treatment: Wound care or physical therapy for the active injury is still running. Confirm the original wound has healed before choosing the sequela character. Query the provider if the note is ambiguous.
• Defaulting to unspecified when laterality is documented: S76.129S belongs only where laterality is genuinely unknown. If the note says “right thigh,” S76.121S is the correct code. Check the assessment and examination sections first.
• Not linking the sequela to the prior injury: The claim goes out with no record of the original laceration. Payers question medical necessity when the chart holds no reference to a prior quadriceps injury. Make sure the problem list or plan of care names it.

Practices that build physical therapy compliance checks into the workflow catch these errors at the documentation stage rather than at claims review.

Payers keep refining their medical necessity edits for musculoskeletal sequela codes. Accurate first-submission coding is cheaper than appealing. The AHA Coding Clinic and the CMS ICD-10-CM annual updates are the references worth keeping open.

How claims management software keeps sequela coding defensible

In a lot of practices, sequela coding problems surface at claims review, weeks after the visit. The coder pulls the chart, finds no reference to the original laceration, and has to chase the provider for an addendum. That is how a clean claim turns into a 30-day delay.

Practice management software like Pabau keeps the whole injury episode in one patient record. The original laceration note, the follow-up wound checks, and today’s rehab visit sit in the same chart, so the sequela link is already documented. Pabau’s claims management software then builds the claim from that record.

Custom note templates can prompt for the healed status and the residual condition at the point of care. You get fewer addendum requests, fewer denied sequela claims, and less time spent rebuilding a documentation trail after the fact.

Streamline sequela and injury code submissions

Pabau helps orthopedic, sports medicine, and physical therapy practices reduce claim errors and document musculoskeletal injuries from the initial encounter through sequela. See how the claims workflow handles it.

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Conclusion

Sequela coding errors are preventable. With S76.129S the risk sits in two places. One is the 7th character. The other is defaulting to unspecified when the note actually states a side. Both errors come from choosing the code before reading the documentation.

Read the chart first and S76.129S becomes one of the easier codes to defend. The prior injury, the healed status, and the residual condition are all a payer wants to see. Book a demo to see how Pabau keeps injury documentation and claim submission in one place.

Continue your research

Looking for guidance on physical therapy compliance documentation? Physiotherapy clinic compliance requirements covers the regulatory standards behind UK and US practice documentation.

Need a rehabilitation framework for post-laceration patients? Return-to-running rehabilitation protocol sets out a structured way to restore function after a lower-limb injury.

Want to improve clinical note quality across injury encounters? Safer clinical documentation practices outlines note-writing habits that support accurate coding and audit-readiness.

Running your own check on sequela claims? Medical chart audit walks through how to review charts before a payer does it for you.

Frequently asked questions