2027 ICD-10-CM Diagnosis Code T86.8421Corneal transplant infection, right eye

ICD-10-CM Codes›S00–T88›T80-T88›T86

ICD-10-CM T86.8421
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T86.8421 is a billable ICD-10-CM diagnosis code for corneal transplant infection, right eye. 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 12 closely related codes. Coders also document this condition as corneal graft infection. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of transplanted organs or tissue, initial encounter.

T86.8421 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 176 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 176, ESRD (V21) category 176, and ESRD (V24) category 176 for payment year 2027.

Code Identity

ICD-10-CM Code
T86.8421
Billable Status
Yes — Valid for Submission
Code Describes
Corneal transplant infection, right eye
Short Description
Corneal transplant infection, right eye
Same as the full description in the CMS dataset.
Parent Code
T86.842
Corneal transplant infection

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 CodeT86.8421Corneal transplant infection, right eye

Medicare Risk Adjustment (HCC)Billing

T86.8421 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 176
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 176 · ESRD (V21): HCC 176 · ESRD (V24): HCC 176
ESRD V21 weights: 0.000 dialysis, 0.599 functioning graft · ESRD V24 weights: 0.000 dialysis, 0.586–1.017 functioning graft
Part D (RxHCC)
Not mapped
T86.8421 does not risk-adjust in the RxHCC prescription drug model

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.

  • Corneal graft infection
  • Disorder due to and following transplant of cornea of right eye
  • Infection of transplanted cornea of right eye

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 T86.8421: its own notes plus those printed at T86.842, T86.84, 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 T86.84 Complications of corneal transplant applies to 20 codes
  • mechanical complications of corneal graft (T85.3-)
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 T86.842 Corneal transplant infection applies to 4 codes
  • code to specify infection
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 T86.8421, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming T86.8421: 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 7

These codes carry an Excludes2 note naming T86.8421: 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
  • T85.3 Mechanical complication of other ocular prosthetic devices, implants and grafts
    other complications of corneal graft (T86.84-) names T86.84-, which includes this code

Code First 4

These codes say to code first a condition named in the note, and T86.8421 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

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

Code History & ChangesHistory

Replacement T86.8421 replaces the following previously assigned code(s):

  • T86.842 - Corneal transplant infection
FY 2021AddedAdded to the ICD-10-CM code setEffective October 1, 2020.
FY 2022–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T86.8421Overview

What is the ICD-10 code for corneal transplant infection, right eye?

The ICD-10-CM code for corneal transplant infection, right eye is T86.8421 (sometimes written as T868421). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T86.8421 (Corneal transplant infection) a billable code?

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

What MS-DRG does T86.8421 group to?

When corneal transplant infection, right eye 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 T86.8421 a CC or MCC?

CMS lists T86.8421 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 12 closely related codes in its exclusion list.

Does T86.8421 need an additional code?

When the condition applies, yes. The Use Additional Code note at T86.842, which applies to T86.8421, reads: code to specify infection. The additional code is reported after T86.8421.

Does T86.8421 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. T86.8421 mapped to HCC 176 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 176 (Complications of Specified Implanted Device or Graft), ESRD (V21) category 176 (Complications of Specified Implanted Device or Graft), and ESRD (V24) category 176 (Complications of Specified Implanted Device or Graft).