ICD-10 Code T22.462S: Corrosion of left scapular region, sequela

Key takeaways

ICD-10 Code T22.462S is the diagnosis code for corrosion of unspecified degree of the left scapular region, sequela.

It covers a late-effect encounter after a chemical burn to that site, once the original injury has healed.

T22.462S is billable for fiscal year 2026, which runs October 1, 2025 through September 30, 2026. Billable means the code carries full specificity for claim submission.

The 7th character ‘S’ marks the sequela encounter. The patient presents for a condition caused by the earlier corrosion, not for the corrosion itself.

Practice management software like Pabau submits ICD-10-CM claims through the Claim.MD clearinghouse and tracks the denials that come back.

ICD-10 Code T22.462S is the billable diagnosis code for corrosion of unspecified degree of the left scapular region, sequela. It applies when a clinician treats a condition caused by an earlier chemical burn to that site, not the burn itself. The 7th character ‘S’ carries that meaning, and it is the only part of the code that changes between encounter types.

This reference covers the code’s billable status and 7th character guidance. It also covers the ICD-10-CM hierarchy, the external cause codes that pair with it, sibling codes, and the documentation a sequela claim needs.

ICD-10 Code T22.462S: definition and clinical description

ICD-10 Code T22.462S is the diagnosis code for corrosion of unspecified degree of the left scapular region, sequela. It sits in Chapter 19 of ICD-10-CM, Injury, Poisoning and Certain Other Consequences of External Causes, inside the S00-T88 range. CMS and NCHS maintain the classification jointly, and the code is listed in the CDC/NCHS ICD-10-CM lookup tool.

Corrosion in ICD-10-CM means injury caused by a chemical or caustic agent rather than a thermal source. The “unspecified degree” component means the record does not classify the depth as superficial, partial thickness, or full thickness. The scapular region covers the posterior shoulder area, including the scapula bone and the soft tissue immediately around it.

Code details at a glance

The table below sets out the reference data for T22.462S as it applies to fiscal year 2026, checked against the CMS ICD-10 codes page.

Understanding the 7th character ‘S’ for sequela encounters

The 7th character is what separates three otherwise identical codes for the same body site and degree. For T22.462S, the ‘S’ says the encounter is for a condition that resulted from a prior corrosion. The corrosion itself is no longer under treatment.

The ICD-10-CM Official Guidelines cover this in Section I.C.19.a, Application of the 7th Characters in Chapter 19. A sequela is a late effect produced by the injury. The initial encounter code no longer applies, because the patient presents for the consequence.

The wrong 7th character is a routine reason these claims come back. If a patient presents with scarring or contracture from a prior chemical burn to the left scapular region, T22.462S is the correct code. If the chemical injury is still under active treatment, A or D applies instead.

T22.462S vs T22.462A vs T22.462D: which code to use

All three codes share the same parent category, T22.462, and describe corrosion of unspecified degree of the left scapular region. The 7th character is the only variable, and it sets both the clinical and the billing context.

Coding T22.462S while the patient is still in active wound care is an audit risk, because T22.462D covers that phase. The distinction hinges on whether the original injury has healed.

On a sequela encounter, the specific residual condition is sequenced first. Scar contracture or fibrosis becomes the principal diagnosis, and T22.462S follows as a secondary code that explains the cause. ICD-10-CM guidelines keep the sequela code out of the principal position whenever the residual condition itself can be coded.

What counts as a corrosion of the left scapular region

Corrosion differs from a thermal burn at the ICD-10-CM level. A burn results from heat, whether fire, steam, a hot object, or radiation. A corrosion results from chemical contact with acids, alkalis, caustic cleaning products, or industrial solvents.

Practices providing wound care, occupational health services, or burn rehabilitation see both. Recording the causative agent and the depth at the initial encounter is what makes the sequela code defensible years later.

How the tabular list separates corrosion from burn

A chemical injury and a thermal burn can look similar on examination, but the ICD-10-CM tabular list routes them into separate code families. Documentation that says only “burn to the left shoulder blade” leaves the coder guessing which family applies.

Within the corrosion range, the depth in the record picks the stem and the 7th character picks the encounter. Each stem carries the same three 7th characters, so the grid below has one cell for every combination at this site.

Where T22.462S sits in the ICD-10-CM hierarchy

The parent path shows what each character narrows. Reading it upward is how you find a more specific code when the record supports one. The full path runs from chapter to code:

• S00-T88: Injury, Poisoning and Certain Other Consequences of External Causes
• T20-T25: Burns and corrosions of external body surface, specified by site
• T22: Burns and corrosions of shoulder and upper limb, except wrist and hand
• T22.4: Corrosion of unspecified degree of shoulder and upper limb
• T22.46: Corrosion of unspecified degree of scapular region
• T22.462: Corrosion of unspecified degree of left scapular region
• T22.462S: Corrosion of unspecified degree of left scapular region, sequela

The AAPC ICD-10-CM lookup and the CDC/NCHS tabular tool both confirm this hierarchy for FY2026. Check that the parent code is still valid before you select a terminal code, because annual revisions occasionally reorganize subcategories.

External cause codes to use with T22.462S

ICD-10-CM guidelines pair a corrosion injury with an external cause code that identifies the chemical agent. That applies on a sequela encounter too. The external cause code explains the mechanism behind the condition now being treated.

Section I.C.20 of the ICD-10-CM Official Guidelines applies external cause codes to every code in the T20-T65 range where the information is available. A corrosion sequela claim submitted without one can draw a request for records. Practices that handle these encounters inside their medical billing workflow can build the pairing into the claim template.

Relevant external cause categories for corrosion injuries include:

• X46 (Accidental poisoning by and exposure to organic solvents and halogenated hydrocarbons and their vapors): used when the record names such an agent
• X49 (Accidental poisoning by and exposure to other and unspecified chemicals and noxious substances): used when the specific chemical agent is not documented
• Place of occurrence codes (Y92.x): added to specify where the original injury occurred (workplace, home, public area)
• Activity codes (Y93.x): document what the patient was doing at the time of the original injury
• External cause status (Y99.x): classifies the encounter as work-related, leisure, or other

On a sequela encounter, these codes describe the circumstances of the original injury rather than the current visit. Confirm each category is still current for the fiscal year before you submit, since the external cause chapter changes annually. The ICD-10-CM code index lists the categories in force this year.

Related ICD-10-CM codes

The T22.462 subcategory sits within a structured family of codes covering corrosion injuries by site, laterality, and degree. The table below lists the closest sibling and adjacent codes for clinical reference.

Coding guidelines and documentation requirements for sequela encounters

Section I.C.19.a of the ICD-10-CM Official Guidelines governs the 7th characters used on injury codes, T22.462S included. Three rules apply consistently to sequela coding:

1. Sequence the sequela condition first: The code for the residual condition, such as scar contracture at L90.5, is the principal diagnosis. T22.462S follows as a secondary code identifying the cause.
2. Do not use a healing phase code: Once the injury has fully healed, D no longer applies. From that point the encounter is a sequela, and S is correct.
3. External cause codes still apply: Append the X-code for the original chemical agent where payer policy asks for it. Not every payer enforces this at a sequela visit, but including it supports medical necessity.

The documentation baseline is a clinical note that names the resolved original injury at every follow-up visit. A note describing only the current condition, such as “posterior shoulder scarring”, leaves the sequela code unsupported. A single line settles it. Write “presenting with post-corrosion hypertrophic scarring following prior chemical injury to left scapular region”.

Approximate synonyms and coding crosswalk

Several alternate terms map to T22.462S in clinical documentation and EHR systems. Coders encountering these descriptions in provider notes should resolve them to this code when the sequela encounter criteria are met:

• Late effect of chemical burn, left scapular region
• Post-corrosion sequela, left shoulder blade area
• Sequela of chemical corrosion, left posterior shoulder
• Corrosion NOS sequela, left scapula

Where the original record can be retrieved, the depth it documents upgrades the code. A first-degree corrosion becomes T22.562S, second degree becomes T22.662S, and third degree becomes T22.762S. Unspecified degree stays correct when the original record is unavailable or silent on depth.

Unspecified-degree injury claims tend to come back with a request for records rather than a flat rejection. Reading the CARC reason code on the remittance tells you which record the payer wants.

Claims management software keeps the diagnosis code, the external cause code, and the encounter note on one claim. The coder checks the pairing before it goes out.

How Pabau keeps corrosion sequela claims together

A practice coding a sequela encounter usually works across three places. The note sits in the clinical record, the codes go onto a billing sheet, and the claim is rekeyed into a payer portal. When the remittance arrives weeks later, nobody can say quickly which encounter it belongs to.

Pabau, practice management software for healthcare practices, holds the encounter note, the assigned codes, and the claim on one patient record. Claims leave through the Claim.MD clearinghouse, and the remittance comes back against the same encounter with its CARC reason code attached.

The coder still decides which 7th character the record supports. What changes is the rework. The original encounter note sits one click from the claim. A payer asking how the scarring relates to the earlier chemical burn gets an answer the same day.

Cut the rework on injury and sequela claims

Pabau stores the encounter note, the codes, and the claim on one record, then submits electronically through Claim.MD. Eligibility checks and remittance reconciliation happen in the same place, so denials land against the encounter that caused them.

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Conclusion

T22.462S is a narrow code, and that is the point of it. It fits only when the original corrosion of the left scapular region has healed and the patient is back for what it left behind.

The 7th character is a documentation decision before it is a coding one. If the note does not say the injury is resolved, the sequela character is not yet supported. Pull the original encounter record while it is still retrievable, because the depth recorded then is what lets you code a degree-specific sequela later.

Most of this comes down to whether the encounter record and the claim live in the same place. Book a demo to see how Pabau routes injury and sequela claims through Claim.MD and lands the denials against the encounter that produced them.

Continue your research

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