2026 ICD-10-CM Diagnosis Code T85.633ALeakage of insulin pump, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T85

ICD-10-CM T85.633A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T85.633A is a billable ICD-10-CM diagnosis code for leakage of insulin pump, 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. 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
T85.633A
Billable Status
Yes — Valid for Submission
Code Describes
Leakage of insulin pump, initial encounter
Short Description
Leakage of insulin pump, initial encounter
Same as the full description in the CMS dataset.
Parent Code
T85.633
Leakage of insulin pump

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 CodeT85.633ALeakage of insulin pump, initial encounter

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 T85.633A to ICD-9-CMHistory

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

ICD-9-CM
996.57 Complcation-insulin pump
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 T85.633AOverview

Is T85.633A (Leakage of insulin pump) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report leakage of insulin pump, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T85.633A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for leakage of insulin pump, such as an emergency visit or first evaluation.

What MS-DRG does T85.633A group to?

When leakage of insulin pump, 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 T85.633A?

Under the General Equivalence Mappings, leakage of insulin pump, initial encounter converts to ICD-9-CM 996.57 (complcation-insulin pump). The mapping is approximate, so confirm the match fits the documentation.