2027 ICD-10-CM Diagnosis Code T86.850Intestine transplant rejection

ICD-10-CM Codes›S00–T88›T80-T88›T86

ICD-10-CM T86.850
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T86.850 is a billable ICD-10-CM diagnosis code for intestine transplant rejection. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 919 through 921. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 52 closely related codes. Coders also document this condition as accelerated rejection of intestine transplant. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of transplanted organs or tissue, initial encounter.

For Medicare Advantage risk adjustment, T86.850 maps to CMS-HCC Category 77 (Intestine Transplant Status/Complications) under the V28 model, adding a risk factor of about 1.172 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
T86.850
Billable Status
Yes — Valid for Submission
Code Describes
Intestine transplant rejection
Short Description
Intestine transplant rejection
Same as the full description in the CMS dataset.
Parent Code
T86.85
Complication of intestine transplant

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 CodeT86.850Intestine transplant rejection

Medicare Risk Adjustment (HCC)Billing

T86.850 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 77— Intestine Transplant Status/Complications
Payment HCC · PY 2027 one of 6 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+1.172
community, non-dual, aged · ranges 1.172–6.301 across segments
Hierarchy
Supersedes HCC 78, HCC 80, and HCC 81
less severe related categories are not paid alongside HCC 77
Prior Model (CMS-HCC V24)
HCC 186
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 186 · ESRD (V21): HCC 186 · ESRD (V24): HCC 186
ESRD V21 weights: 0.154 dialysis, 0.075 functioning graft · ESRD V24 weights: 0.138 dialysis, 0.000 functioning graft
Part D (RxHCC)
RxHCC 396 — Heart, Lung, Liver, Intestine, or Pancreas Transplant Status
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Accelerated rejection of intestine transplant
  • Acute rejection of intestine transplant
  • Chronic rejection of intestine transplant
  • Complication of transplanted intestines
  • Hyperacute rejection of intestine transplant
  • Rejection of intestine transplant

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 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T86.850: its own notes plus those printed at T86, block T80-T88, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block T80-T88 Complications of surgical and medical care, not elsewhere classified applies to 1,683 codes
  • any encounters with medical care for postprocedural conditions in which no complications are present, such as:
  • artificial opening status (Z93.-)
  • closure of external stoma (Z43.-)
  • fitting and adjustment of external prosthetic device (Z44.-)
  • burns and corrosions from local applications and irradiation (T20-T32)
  • complications of surgical procedures during pregnancy, childbirth and the puerperium (O00-O9A)
  • mechanical complication of respirator [ventilator] (J95.850)
  • poisoning and toxic effects of drugs and chemicals (T36-T65 with fifth or sixth character 1-4 or 6)
  • postprocedural fever (R50.82)
  • specified complications classified elsewhere, such as:
  • cerebrospinal fluid leak from spinal puncture (G97.0)
  • colostomy malfunction (K94.0-)
  • disorders of fluid and electrolyte imbalance (E86-E87)
  • functional disturbances following cardiac surgery (I97.0-I97.1)
  • intraoperative and postprocedural complications of specified body systems (D78.-, E36.-, E89.-, G97.3-, G97.4, H59.3-, H59.-, H95.2-, H95.3, I97.4-, I97.5, J95.6-, J95.7, K91.6-, L76.-, M96.-, N99.-)
  • ostomy complications (J95.0-, K94.-, N99.5-)
  • postgastric surgery syndromes (K91.1)
  • postlaminectomy syndrome NEC (M96.1)
  • postmastectomy lymphedema syndrome (I97.2)
  • postsurgical blind-loop syndrome (K91.2)
  • ventilator associated pneumonia (J95.851)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From T86 Complications of transplanted organs and tissue applies to 77 codes
  • code to identify other transplant complications, such as:
  • graft-versus-host disease (D89.81-)
  • malignancy associated with organ transplant (C80.2)
  • post-transplant lymphoproliferative disorders (PTLD) (D47.Z1)
From Block T80-T88 Complications of surgical and medical care, not elsewhere classified applies to 1,683 codes
  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
  • code(s) to identify the specified condition resulting from the complication
  • code to identify devices involved and details of circumstances (Y62-Y82)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name T86.850, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming T86.850: they are not reported together with it, unless the two conditions are unrelated.

  • Z98.85 Transplanted organ removal status
    encounter for removal of transplanted organ -code to complication of transplanted organ (T86.-) names T86.-, which includes this code

Excludes2 6

These codes carry an Excludes2 note naming T86.850: its condition is not part of those codes, and both may be reported when the patient has both.

  • D89 Other disorders involving the immune mechanism, not elsewhere classified
    transplant failure and rejection (T86.-) names T86.-, which includes this code
  • T81 Complications of procedures, not elsewhere classified
    complications of transplanted organs and tissue (T86.-) names T86.-, which includes this code
  • T82 Complications of cardiac and vascular prosthetic devices, implants and grafts
    failure and rejection of transplanted organs and tissue (T86.-) names T86.-, which includes this code
  • T83 Complications of genitourinary prosthetic devices, implants and grafts
    failure and rejection of transplanted organs and tissue (T86.-) names T86.-, which includes this code
  • T84 Complications of internal orthopedic prosthetic devices, implants and grafts
    failure and rejection of transplanted organs and tissues (T86.-) names T86.-, which includes this code
  • T85 Complications of other internal prosthetic devices, implants and grafts
    failure and rejection of transplanted organs and tissue (T86.-) names T86.-, which includes this code

Code First 4

These codes say to code first a condition named in the note, and T86.850 is one of the conditions named.

  • C80.2 Malignant neoplasm associated with transplanted organ
    complication of transplanted organ (T86.-) names T86.-, which includes this code
  • D47.Z1 Post-transplant lymphoproliferative disorder (PTLD)
    complications of transplanted organs and tissue (T86.-) names T86.-, which includes this code
  • D89.81 Graft-versus-host disease
    complications of transplanted organs and tissue (T86.-) names T86.-, which includes this code
  • D89.83 Cytokine release syndrome
    complications of transplanted organs and tissue (T86.-) names T86.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 T86.850 to ICD-9-CMHistory

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

ICD-9-CM
996.87 Comp intestine transplnt
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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T86.850Overview

What is the ICD-10 code for intestine transplant rejection?

The ICD-10-CM code for intestine transplant rejection is T86.850 (sometimes written as T86850). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T86.850 (Complication of intestine transplant) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report intestine transplant rejection on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does T86.850 group to?

When intestine transplant rejection is the principal diagnosis on an inpatient stay, it groups to MS-DRG 920, 919, 921, with relative weights from 0.6719 to 1.7624 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T86.850 a CC or MCC?

CMS lists T86.850 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 52 closely related codes in its exclusion list.

Does T86.850 need an additional code?

When the condition applies, yes. The Use Additional Code note at T86, which applies to T86.850, reads: code to identify other transplant complications, such as: graft-versus-host disease (D89.81-); malignancy associated with organ transplant (C80.2); post-transplant lymphoproliferative disorders (PTLD) (D47.Z1). The additional code is reported after T86.850.

What HCC is T86.850?

T86.850 (intestine transplant rejection) maps to CMS-HCC Category 77 (Intestine Transplant Status/Complications), commonly written as HCC 77, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 186 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 396.

Does T86.850 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, T86.850 adds a risk adjustment factor of about 1.172 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 1.172 to 6.301 depending on the payment segment). HCC 77 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 77 category page.