What is ICD-10 code T86.03?

T86.03 is the ICD-10-CM diagnosis code for Bone marrow transplant infection. An infection develops as a complication of bone marrow transplant, often due to the immunosuppressed state of the transplant recipient. T86.03 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. T86.03 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. T86.03 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. T86.03 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for T86.03?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For T86.03, V28 maps to Stem Cell, Including Bone Marrow, Transplant Status/Complications at RAF 1.068 while V24 mapped to Major Organ Transplant or Replacement Status at RAF 0.832. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting T86.03?

Code the specific infectious organism separately if identified (e.g., CMV, fungal infection, bacterial sepsis) Include seventh character for episode of care and ensure the infection code is linked to the transplant complication Because T86.03 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

2026 ICD-10-CM T86.03: Bone marrow transplant

ICD-10-CM Code View

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Code lookupT86.03Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Complications of surgical and medical care, not elsewhere classified (T80-T88)

T86.03

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Bone marrow transplant infection

An infection develops as a complication of bone marrow transplant, often due to the immunosuppressed state of the transplant recipient.

Buddy Insight

This represents infection occurring as a complication of bone marrow transplant, often due to the patient's immunosuppressed state and compromised immune function.

CMS-HCC V28

Mapped

HCC 454

Stem Cell, Including Bone Mar...

RAF 1.068

CMS-HCC V24

Mapped

HCC 186

Major Organ Transplant or Rep...

RAF 0.832

ACA/HHS

Mapped

HCC 251

HHS-HCC 251

Varies by metal level

ESRD/PACE

Mapped

HCC 186

Major Organ Transplant or Rep...

RAF 0.138

RXHCC

Mapped

HCC 395

Graft-Versus-Host Disease

RAF 4.379

Code Book Path

Official

T86Complications of transplanted organs and tissue

T86.0Complications of bone marrow transplant

T86.03Bone marrow transplant infection

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for T86.03 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for T86.03 in this effective period.

Related Child Codes

Official

T86.00Unspecified complication of bone marrow transplant

T86.01Bone marrow transplant rejection

T86.02Bone marrow transplant failure

T86.09Other complications of bone marrow transplant

Includes

Official

ICD-10-CM does not list Includes notes for T86.03 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for T86.03 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for T86.03 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for T86.03 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for T86.03 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of infection in transplant recipient

Type and location of infection

Causative organism if identified

Relationship to immunosuppressed state

MEAT Support

HCC Buddy guidance

Documentation of infection in transplant recipient

Type and location of infection

Causative organism if identified

Relationship to immunosuppressed state

Audit Caution

HCC Buddy guidance

Using only the infection code without the transplant complication code

Missing additional codes for specific infectious organisms

Failing to link infection to transplant status

Using unspecified codes when infection type is known

Common Mistakes

HCC Buddy guidance

T86.00 — Unspecified bone marrow transplant complication

T86.09 — Other bone marrow transplant complications

Specific infection codes — Should be coded additionally

Z87.891 — Personal history of nicotine dependence

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is T86.03 an HCC code?

Yes. T86.03 (Bone marrow transplant infection) maps to Stem Cell, Including Bone Marrow, Transplant Status/Complications under the CMS-HCC V28 risk adjustment model (and Major Organ Transplant or Replacement Status under V24), with a community non-dual aged RAF of 1.068. It is billable for payment year 2026.

Coder answer: T86.03 is billable and maps to V28 HCC 454, Stem Cell, Including Bone Marrow, Transplant Status/Complications. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: T86.03
Description: Bone marrow transplant infection
HCC (V28): HCC 454 — Stem Cell, Including Bone Marrow, Transplant Status/Complications
RAF: 1.068
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 454, Stem Cell, Including Bone Marrow, Transplant Status/Complications

1.068

V24HCC 186, Major Organ Transplant or Replacement Status

0.832

ESRDHCC 186, Major Organ Transplant or Replacement Status

0.138

RxHCCHCC 395, Graft-Versus-Host Disease

4.379

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work T86.03 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for T86.03

For T86.03 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed T86.03 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

T86.03 is the ICD-10-CM diagnosis code for bone marrow transplant infection. An infection develops as a complication of bone marrow transplant, often due to the immunosuppressed state of the transplant recipient. T86.03 sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering complications of surgical and medical care, not elsewhere classified (t80-t88).

Under the CMS-HCC V28 risk adjustment model, T86.03 maps to Stem Cell, Including Bone Marrow, Transplant Status/Complications (HCC 454) with a community, non-dual, aged base RAF weight of 1.068. Under the older CMS-HCC V24 model, T86.03 maps to Major Organ Transplant or Replacement Status (HCC 186) with a community, non-dual, aged base RAF weight of 0.832. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Code the specific infectious organism separately if identified (e.g., CMV, fungal infection, bacterial sepsis). Because T86.03 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for T86.03 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Code the specific infectious organism separately if identified (e.g., CMV, fungal infection, bacterial sepsis)
•Include seventh character for episode of care and ensure the infection code is linked to the transplant complication

Clinical Significance

This represents infection occurring as a complication of bone marrow transplant, often due to the patient's immunosuppressed state and compromised immune function. These infections can be life-threatening and require immediate intervention with antimicrobial therapy, representing a common but serious complication requiring specialized infectious disease management.