2026 ICD-10-CM Diagnosis Code T86.99Other complications of unspecified transplanted organ and tissue

ICD-10-CM Codes›S00–T88›T80-T88›T86

ICD-10-CM T86.99
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T86.99 is a billable ICD-10-CM diagnosis code for other complications of unspecified transplanted organ and tissue. 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. 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
T86.99
Billable Status
Yes — Valid for Submission
Code Describes
Other complications of unspecified transplanted organ and tissue
Short Description
Other complications of unsp transplanted organ and tissue
Parent Code
T86.9
Complication of unspecified transplanted organ 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 CodeT86.99Other complications of unspecified transplanted organ and tissue

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Donor derived melanoma
  • Graft reaction AND/OR rejection
  • Iatrogenic immunodeficiency-associated lymphoproliferative disorder
  • Limbic encephalitis
  • Lymphocyte passenger syndrome following organ transplantation
  • Lymphoproliferative disorder following transplantation
  • Monomorphic posttransplant lymphoproliferative disorder
  • Polymorphic lymphoproliferative disorder following transplant
  • Post-transplant acute limbic encephalitis
  • Posttransplant diabetes mellitus
  • Posttransplant hyperlipidemia
  • Post-transplant neoplasia
  • Sloughed graft

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.

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
        • specified
          • type NEC

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

Clinical InformationClinical

  • Limbic Encephalitis

    a paraneoplastic syndrome marked by degeneration of neurons in the limbic system. clinical features include hallucinations, loss of episodic memory; anosmia; ageusia; temporal lobe epilepsy; dementia; and affective disturbance (depression). circulating anti-neuronal antibodies (e.g., anti-hu; anti-yo; anti-ri; and anti-ma2) and small cell lung carcinomas or testicular carcinoma are frequently associated with this syndrome.

  • Limbic Encephalitis

    a rare disorder characterized by degenerative changes in the limbic area of the brain. causes include infections and autoimmune conditions; it may also manifest as a paraneoplastic syndrome, most often caused by small cell lung carcinoma. signs and symptoms include behavioral changes, hallucinations and dementia.

Patient EducationClinical

Organ Transplantation

You may need an organ transplant if one of your organs has failed. This can happen because of illness or injury. When you have an organ transplant, doctors remove an organ from another person and place it in your body. The organ may come from a living donor or a donor who has died.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T86.99 to ICD-9-CMHistory

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

ICD-9-CM
996.80 Comp organ transplnt NOS
Approximate The match is approximate rather than exact.

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 T86.99Overview

Is T86.99 (Complication of unspecified transplanted organ and tissue) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other complications of unspecified transplanted organ and tissue on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does T86.99 group to?

When other complications of unspecified transplanted organ and tissue 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 T86.99?

Under the General Equivalence Mappings, other complications of unspecified transplanted organ and tissue converts to ICD-9-CM 996.80 (comp organ transplnt NOS). The mapping is approximate, so confirm the match fits the documentation.

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.