ICD-10 code T86.02: Bone marrow transplant failure

ICD-10 code T86.02 is the billable ICD-10-CM diagnosis code for bone marrow transplant failure. It is valid for HIPAA-covered transactions from October 1, 2025 through September 30, 2026, and it covers both primary non-engraftment and secondary graft failure.

Coders frequently confuse T86.02 with T86.01, which codes rejection. T86.02 applies when the donor marrow does not engraft, or when engraftment is lost after it happens. T86.01 applies when the host immune system attacks and destroys the graft.

This reference covers the code details, the clinical criteria that separate failure from rejection, and the T86.0x sibling family. It also covers the sequencing rules and the codes most commonly reported alongside T86.02 in hematology and oncology encounters.

Found our content helpful?

Key takeaways

T86.02 is a billable ICD-10-CM code for bone marrow transplant failure, covering both primary and secondary graft failure subtypes.

It is valid for fiscal year 2026 (October 1, 2025 through September 30, 2026) and accepted for HIPAA-covered electronic transactions.

T86.02 codes graft failure, where the marrow does not engraft or engraftment is lost after it happens.

T86.01 codes rejection, an immune-mediated attack on the graft, so selecting the wrong code misrepresents the clinical event.

Practice management software like Pabau supports accurate ICD-10-CM code submission and electronic claim routing for hematology and oncology practices.

ICD-10 code T86.02: Code information at a glance

T86.02 is a specific, billable ICD-10-CM code. The table below captures every field a coder or biller needs to confirm before submitting a claim.

The CDC/NCHS ICD-10-CM web tool confirms fiscal year validity and billable status for the current code year. Always verify against the active tabular list before submitting.

Clinical description of bone marrow transplant failure

Bone marrow transplant failure, coded as T86.02, occurs when the transplanted hematopoietic stem cells do not produce adequate blood cell counts in the recipient. Two subtypes are captured under this code:

• Primary graft failure: The transplanted marrow never engrafts. The recipient’s blood counts fail to recover within the expected post-transplant window (typically day 28 or later, depending on the conditioning regimen).
• Secondary graft failure: Initial engraftment occurs, blood counts recover, but then decline again as the graft is lost. This is often associated with immune rejection, viral infection (CMV, HHV-6), or disease relapse.

Both primary and secondary graft failure are coded T86.02 under the ICD-10-CM tabular structure. The subtype changes the clinical picture without changing the code. Rejection is a separate event, and it routes to T86.01. Plotting the post-transplant courses side by side shows how far the documentation has to carry the code selection.

The SNOMED CT browser maps related hematopoietic stem cell transplant complications, which helps practices that report in both SNOMED CT and ICD-10-CM.

Inclusion terms and synonyms for T86.02

ICD-10-CM inclusion terms guide coders toward T86.02 when a diagnosis is documented using clinical language rather than the code’s official description. The following terms and synonyms map to T86.02:

• Bone marrow transplant failure
• BMT failure
• Graft failure (bone marrow)
• Primary graft failure (bone marrow transplant)
• Secondary graft failure (bone marrow transplant)
• Hematopoietic stem cell transplant (HSCT) failure
• Stem cell graft failure

When the attending physician documents any of these phrases in the discharge summary or clinical note, T86.02 is the correct ICD-10-CM code to assign. That holds provided the documentation supports failure rather than rejection. See the failure versus rejection rules below.

Where T86.02 sits in the ICD-10-CM hierarchy

T86.02 sits within the ICD-10-CM chapter structure as follows:

Category T86 also covers complications of transplanted kidney (T86.1x), heart (T86.2x), lung (T86.3x), liver (T86.4x), skin (T86.8x), and other organs. A post-transplant complication in another organ therefore leaves the T86.0x subcategory entirely.

Sibling codes in the T86.0x family

The T86.0x subcategory covers five distinct bone marrow transplant complication codes. Using the most specific code available is required under ICD-10-CM Official Guidelines.

T86.00 is a valid last resort when the physician documents a BMT complication without naming the type. Most payers require greater specificity, so query the physician before defaulting to the unspecified code. Our ICD-10-CM code reference covers the neighboring categories a transplant admission tends to pull in.

When to use T86.02 vs T86.01: Failure vs rejection

Graft failure and graft rejection are distinct events, and the ICD-10-CM code selection must reflect exactly what the physician documented. Selecting the wrong code changes the coded diagnosis, affects DRG assignment, and can trigger payer denials on medical necessity or clinical inconsistency grounds.

If the record is ambiguous, a clinical documentation integrity (CDI) query to the attending hematologist is warranted before code assignment. Never assume failure when rejection is clinically possible, or vice versa. Solid denial management starts at this documentation step.

Coding guidelines and documentation requirements

The ICD-10-CM Official Guidelines for Coding and Reporting govern how T86.02 is sequenced and what additional codes must accompany it. Key rules for hematology and oncology coders:

• Sequencing as principal diagnosis: T86.02 may be the principal diagnosis when transplant failure is chiefly responsible for the admission after study. The underlying cause of transplant (e.g. aplastic anemia, D61.x; leukemia, C90-C95) is sequenced as an additional diagnosis.
• Use additional code instructions: Code also any associated complication, including graft-versus-host disease (D89.81x) and post-transplant immunodeficiency where documented.
• External cause code: T86.02 is a complication-of-care code and does not require a separate external cause code from Chapter 20 (V00-Y99).
• 7th character requirement: T86.02 does not carry a 7th character extension. The code is complete at 5 characters.

For facilities submitting claims electronically, T86.02 has to travel with the matching DRG and modifier combination. Cleaner claims management at that step keeps a transplant complication encounter from coming back as a rebill.

Documentation the coder needs to assign T86.02 with confidence:

• Physician attestation that the complication is bone marrow transplant failure (not rejection, not unspecified)
• Date of original transplant (relevant for linking complication to the procedure)
• Blood count data confirming non-engraftment or loss of engraftment
• Underlying diagnosis that necessitated the transplant

Payer rules for transplant complication codes vary. Some commercial plans require pre-authorization documentation to accompany claims for post-transplant complication management, so confirm the payer’s requirement before the claim is built.

Codes commonly reported alongside T86.02

T86.02 rarely appears on a claim by itself. Hematology encounters for bone marrow transplant failure typically involve multiple concurrent diagnoses, each requiring its own code.

Graft-versus-host disease ICD-10 code (D89.81x)

Graft-versus-host disease (GVHD) is coded separately from graft failure. GVHD represents the donor immune cells attacking the host, while graft failure (T86.02) represents the failure of donor cells to establish. They can co-exist but are clinically and mechanistically distinct. According to the CMS ICD-10-CM codes page, GVHD subcodes include:

• D89.810: Acute graft-versus-host disease
• D89.811: Chronic graft-versus-host disease
• D89.812: Acute-on-chronic graft-versus-host disease
• D89.813: Graft-versus-host disease, unspecified

When GVHD occurs alongside documented graft failure, code both T86.02 and the appropriate D89.81x. The sequencing follows which condition drove the admission.

Other commonly paired codes

A code combination checklist for T86.02 encounters helps coders capture every relevant diagnosis consistently. It also reduces the risk of under-coding a complex hematology case.

Code history and annual updates through FY2026

T86.02 has been active since the introduction of ICD-10-CM in the United States. The code has not been revised or retired through FY2026.

The AAPC Codify ICD-10-CM lookup provides year-specific code validity and cross-references for the full T86 category. Confirm annual status each October when CMS releases the new code year. A prior-year code on a FY2026 claim is rejected, so flag the October 1 switchover in the billing calendar.

How Pabau keeps T86.02 claims accurate at submission

Most hematology practices build a transplant complication claim in two places. The coder assigns T86.02 and its companion codes in the record, then someone re-keys the set into a clearinghouse portal. Every re-key is another chance for the code to drift from what the physician documented.

Pabau carries the coded diagnosis straight from the clinical record onto the claim. Built-in ICD-10-CM and CPT catalogues mean the coder picks T86.02 once. The Claim.MD integration then turns the invoice into an electronic claim, with no clearinghouse portal and no X12 file to build.

That shortens the path between the hematologist’s documentation and the submitted claim. Fewer hands touch the code, so a T86.02 encounter is less likely to reach a payer as T86.01 or T86.00.

Send transplant complication claims without re-keying

Pabau builds the ICD-10-CM code set on the claim inside the patient record, then submits it electronically through Claim.MD. Your coders enter T86.02 once and it travels to the payer unchanged.

Book a demo

Conclusion

Treat the T86.0x selection as a documentation question rather than a coding one. The blood counts will not tell you whether the graft failed or the host rejected it. Neither will the discharge summary, unless the hematologist writes the mechanism down.

Build the query into the workflow at the point the complication is first coded. Waiting until the denial arrives costs a rebill and a second round of documentation.

A practice that queries early submits T86.02 once and keeps the record consistent with what the transplant team saw. Book a demo to see how Pabau moves a coded hematology encounter to the payer without a re-key.

Continue your research

Need to understand how claims route from code to payer? Medical claims clearinghouse guide explains how electronic claim submission works across payer networks.

Coding a denial on a transplant complication claim? Denial codes in medical billing covers the most common CARC codes and how to respond to them.

Submitting 837P claims for complex hematology encounters? 837 file guide breaks down the electronic claim format and common submission errors.

Frequently asked questions