2026 ICD-10-CM Diagnosis Code T85.858AStenosis due to other internal prosthetic devices, implants and grafts, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T85

ICD-10-CM T85.858A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T85.858A is a billable ICD-10-CM diagnosis code for stenosis due to other internal prosthetic devices, implants and grafts, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. 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 internal prosthetic device causing stenosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of other surgical or medical care, injury, initial encounter.

Code Identity

ICD-10-CM Code
T85.858A
Billable Status
Yes — Valid for Submission
Code Describes
Stenosis due to other internal prosthetic devices, implants and grafts, initial encounter
Short Description
Stenosis due to other internal prosth dev/grft, init
Parent Code
T85.858
Stenosis due to other internal prosthetic devices, implants and grafts

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT85Complications of other internal prosthetic devices, implants and grafts
This CodeT85.858AStenosis due to other internal prosthetic devices, implants and grafts, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Internal prosthetic device causing stenosis

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Complications of other internal prosthetic devices, implants and grafts (T85). 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.

Clinical ClassificationClinical

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

CCSR INJ037
Complication of other surgical or medical care, injury, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert T85.858A to ICD-9-CMHistory

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

ICD-9-CM
996.79 Comp-int prost devic NEC
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement T85.858A replaces the following previously assigned code(s):

  • T85.85XA - Stenosis due to internal prosth dev/grft, NEC, init
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T85.858AOverview

Is T85.858A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report stenosis due to other internal prosthetic devices, implants and grafts, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T85.858A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for stenosis due to other internal prosthetic devices, implants and grafts, such as an emergency visit or first evaluation.

What MS-DRG does T85.858A group to?

When stenosis due to other internal prosthetic devices, implants and grafts, initial encounter 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 T85.858A?

Under the General Equivalence Mappings, stenosis due to other internal prosthetic devices, implants and grafts, initial encounter converts to ICD-9-CM 996.79 (comp-int prost devic NEC). The mapping is approximate, so confirm the match fits the documentation.