ICD-10 Code T86.812: Lung transplant infection

Key takeaways

T86.812 is a billable ICD-10-CM code for lung transplant infection, effective October 1, 2025 for FY2026.

It sits under T86.81, the subcategory for lung transplant complications, inside the T86 category for transplanted organs.

A Use additional code note requires a second code naming the infectious organism, such as B25.0 for CMV.

Heart-lung transplant complications belong in the T86.3- subcategory, not under T86.81.

Practice management software like Pabau keeps the note, the lab result, and the transplant history in one chart.

ICD-10 Code T86.812 is a billable ICD-10-CM diagnosis code for infection in a transplanted lung. It applies when a lung transplant recipient develops an active infection in the graft, whatever the causative organism. The tabular list pairs it with a second code naming that organism, and usually with Z94.2 for transplant status. This reference covers the hierarchy, the sibling codes, the documentation each assignment needs, and the sequencing payers expect.

ICD-10 Code T86.812: definition and billable status

ICD-10 Code T86.812, as published in the CDC/NCHS ICD-10-CM web tool, is a billable and specific diagnosis code for lung transplant infection. It is valid for all HIPAA-covered transactions in the FY2026 code year, effective October 1, 2025. Billable and specific means the code carries enough detail to go on a claim without a more granular child code.

It captures one clinical scenario. A patient with a prior lung transplant develops an active infection in the transplanted organ. The infection may be bacterial, viral, or fungal. T86.812 does not name the causative organism on its own, so ICD-10-CM requires a secondary code that does.

T86.812 code hierarchy and ICD-10-CM classification

Knowing where T86.812 sits in the ICD-10-CM tabular list helps coders apply it correctly and find related codes quickly. Each level of the structure below adds a further degree of clinical specificity.

T86.81 is not billable on its own. It is the parent subcategory for all lung transplant complications, and one of its five child codes carries the claim. T86.812 is the only child code under T86.81 that captures infection specifically.

T86.81 also carries an Excludes1 note for complication of heart-lung transplant (T86.3-). Excludes1 means the two are never coded together. When the graft is a combined heart-lung transplant, code from the T86.3- subcategory instead, such as T86.31.

Related codes: T86.810, T86.811, T86.818, and T86.819

Four sibling codes share the T86.81 subcategory with T86.812, and the documented complication type decides which one applies. Rejection is an immune response. Failure is loss of graft function. Infection is a separate pathologic process driven by a pathogen. Consult CMS ICD-10 codes guidance for annual updates to descriptions and effective dates.

The same five-way split repeats across the category, so T86.10 does for kidney transplants what T86.819 does here. Treat the unspecified code as a last resort. When the documentation describes infection, assign T86.812 rather than T86.819.

Documentation requirements for T86.812

Three documentation elements must be present before T86.812 can be assigned, and missing any one of them creates an audit vulnerability. Digital clinical documentation tools help capture all three consistently at the point of care.

• Confirmation of lung transplant status: The record must establish that the patient has received a lung transplant. ICD-10-CM coding guidelines recommend assigning Z94.2 (Lung transplant status) as an additional code when a transplant status is relevant to the encounter.
• Documented active infection in the transplanted lung: The physician must explicitly state that the infection is present in the transplanted organ. Documentation describing pulmonary infection in a transplant recipient without specifying the graft as the affected site may not support T86.812.
• Infectious organism or type identified: The ICD-10-CM tabular list carries a Use additional code note under T86.812. It directs you to a second code for the infection. This is a mandatory dual-coding instruction, not advisory.

Maintaining HIPAA-compliant documentation across post-transplant encounters supports both coding accuracy and audit defense. That matters most when a record travels between the transplant center, the infectious disease team, and the billing department.

When to use an additional code

The ICD-10-CM tabular list carries a Use additional code note under T86.812, directing the coder to specify the infection. That pairing is mandatory. Submitting T86.812 alone leaves the claim incomplete by ICD-10-CM standards and can trigger medical necessity queries. The AAPC ICD-10-CM lookup shows the note alongside the code entry.

T86.812 is the principal diagnosis when the transplant infection is the reason for the encounter. The organism code follows as the additional code. In claims management software, both codes belong in the diagnosis field, with T86.812 in first position.

Common infectious organisms and their ICD-10-CM codes

Lung transplant recipients are immunosuppressed by design, which leaves them open to a particular range of opportunistic and bacterial pathogens. The table below lists the organisms seen most often in post-lung-transplant infection, with their ICD-10-CM codes.

Verify each organism code against the current FY2026 ICD-10-CM tabular list before submission. Descriptions and available specificity change between annual editions, so this table supports a lookup rather than replacing one.

Lung transplant status code: Z94.2 and sequencing

Z94.2 identifies a patient who has undergone a lung transplant. It records transplant history and carries no complication of its own. On a T86.812 encounter, add Z94.2 as an additional code so the record shows that the affected lung is a graft. CMS ICD code lists cover how status codes sequence alongside complication codes on Medicare claims.

Sequencing for a T86.812 encounter follows the pattern below. It mirrors the order a physical therapy EMR uses for post-operative records, with the active condition first and the status code behind it.

1. T86.812 (Lung transplant infection) as the principal diagnosis when infection drives the encounter
2. Organism code (e.g. B25.0 for CMV) as an additional code to satisfy the Use additional code note
3. Z94.2 (Lung transplant status) as an additional code to document transplant history

If the patient is admitted for a separate reason and the transplant infection is discovered incidentally, sequencing may change. ICD-10-CM Official Guidelines for Coding and Reporting govern sequencing in those scenarios.

Approximate synonyms and index references

Coders working the ICD-10-CM alphabetic index will meet several alternate descriptions, and every term below maps to T86.812. Accurate patient record management captures the physician’s own wording, so coding staff can find the right code faster.

• Lung transplant infection
• Infected lung transplant
• Post-transplant pulmonary infection
• Infection of transplanted lung
• Transplant lung infection
• Pulmonary graft infection

When you query a physician for clarification, mirror the terminology they already use. A query asking whether a pulmonary graft infection is present usually lands better than one asking for T86.812 by number.

Coding rules across the T86 category

The T86 category covers complications of every transplanted organ and tissue. ICD-10-CM groups them by organ type, with parallel subcategories for rejection, failure, infection, other specified, and unspecified. Cell and tissue grafts sit here too, so regenerative medicine practices code from the same category. The liver equivalent of T86.810 is T86.41, and the heart-lung equivalents live in T86.3-.

Three key distinctions for coding transplant complications correctly:

• Rejection vs. infection: Rejection (T86.810) is an immune-mediated process and may be treated with increased immunosuppression. Infection (T86.812) is a pathogenic process and may be treated with antimicrobials. These are not interchangeable. If both occur simultaneously, assign both codes.
• Failure vs. infection: Transplant failure (T86.811) indicates loss of graft function, not necessarily the presence of an active pathogen. Infection may lead to failure, but the codes represent distinct conditions. Document and assign both when present.
• Specificity over unspecified: T86.819 (Unspecified complication) should only be used when the documentation genuinely does not support a more specific code. Query the physician before defaulting to unspecified.

How Pabau keeps T86.812 claims complete

Most practices build a transplant complication claim from three separate places. The physician’s note names the infected site, the lab report names the organism, and the history supplies the transplant status. Coders reconcile all three by hand, and the organism code is the one that slips.

Practice management software like Pabau holds those three sources against one patient record. Lab results, clinical notes, and past procedures sit on the same chart, so a coder reads the culture result and the graft description together. Custom forms can prompt the clinician to state the site and the organism while the patient is still in the room.

The outcome is a shorter path from documentation to a clean claim. When the note, the lab result, and the transplant history sit together, the coder assigns T86.812 and its organism code in one pass.

Keep transplant complication claims complete

Pabau keeps clinical notes, lab results, and transplant history in one patient record, so coders can see every fact a T86.812 claim needs. That cuts the back-and-forth before submission.

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Conclusion

Two facts in the record decide whether T86.812 holds up. The note has to name the graft as the infected site, and the lab has to name the organism. Chase both before the claim goes out, because a retrospective query after a denial costs far more time.

Defaulting to T86.819 throws away specificity the documentation already supports. Submitting T86.812 on its own invites a payer query for the organism. Both outcomes are settled at the point of documentation rather than at the point of billing.

Pabau keeps the note, the lab result, and the transplant history in one chart. The second code stays visible while the first is being assigned. Book a demo to see how it supports post-transplant coding and documentation.

Continue your research

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Coding a complication in a different transplanted organ? T86.298 covers the heart transplant equivalent, including its documentation and sequencing rules.

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