2026 ICD-10-CM Diagnosis Code T86.5Complications of stem cell transplant

ICD-10-CM Codes›S00–T88›T80-T88›T86

ICD-10-CM T86.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T86.5 is a billable ICD-10-CM diagnosis code for complications of stem cell transplant. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 919 through 921. Coders also document this condition as bronchiolitis obliterans syndrome following allogeneic stem cell transplant. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of transplanted organs or tissue, initial encounter.

Code Identity

ICD-10-CM Code
T86.5
Billable Status
Yes — Valid for Submission
Code Describes
Complications of stem cell transplant
Short Description
Complications of stem cell transplant
Same as the full description in the CMS dataset.
Parent Code
T86
Complications of transplanted organs and tissue

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT86Complications of transplanted organs and tissue
This CodeT86.5Complications of stem cell transplant

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bronchiolitis obliterans syndrome following allogeneic stem cell transplant
  • Chronic bronchiolitis
  • Chronic graft-versus-host disease
  • Chronic obliterative bronchiolitis
  • Disorder due to and following transplantation of stem cell
  • Thrombotic microangiopathy following transplantation of hematopoietic stem cell

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Complications of transplanted organs and tissue (T86). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Complications from stem cells from peripheral blood
  • Complications from stem cells from umbilical cord

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Complication(s) (from) (of)
      • transplant
        • peripheral blood stem cells
    • Complication(s) (from) (of)
      • transplant
        • stem cell (from peripheral blood) (from umbilical cord)
    • Complication(s) (from) (of)
      • transplant
        • umbilical cord stem cells
    • Failure, failed
      • transplant
        • stem cell (peripheral blood) (umbilical cord)
    • Rejection
      • transplant
        • stem cell (peripheral blood) (umbilical cord)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ036
Complication of transplanted organs or tissue, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert T86.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
996.88 Comp tp organ-stem cell
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T86.5Overview

Is T86.5 (Complications of transplanted organs and tissue) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report complications of stem cell transplant on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does T86.5 group to?

When complications of stem cell transplant is the principal diagnosis on an inpatient stay, it groups to MS-DRG 919, 920, 921, with relative weights from 0.6884 to 1.8308 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of T86.5?

Under the General Equivalence Mappings, complications of stem cell transplant converts to ICD-9-CM 996.88 (comp tp organ-stem cell). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.