2026 ICD-10-CM Diagnosis Code T82.598AOther mechanical complication of other cardiac and vascular devices and implants, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T82

ICD-10-CM T82.598A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T82.598A is a billable ICD-10-CM diagnosis code for other mechanical complication of other cardiac and vascular devices and implants, 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 314 through 316. 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 59 closely related codes. Coders also document this condition as complete obstruction of cardiac conduit. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of cardiovascular device, implant or graft, initial encounter.

T82.598A 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 2026.

Code Identity

ICD-10-CM Code
T82.598A
Billable Status
Yes — Valid for Submission
Code Describes
Other mechanical complication of other cardiac and vascular devices and implants, initial encounter
Short Description
Mech compl of cardiac and vascular devices and implnt, init
Parent Code
T82.598
Other mechanical complication of other cardiac and vascular devices and implants

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT82Complications of cardiac and vascular prosthetic devices, implants and grafts
This CodeT82.598AOther mechanical complication of other cardiac and vascular devices and implants, initial encounter

Medicare Risk Adjustment (HCC)Billing

T82.598A 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
T82.598A does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2026 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.

  • Complete obstruction of cardiac conduit
  • Failure of systemic to pulmonary arterial shunt
  • Fracture of stent of coronary artery
  • Obstruction of right atrial conduit after prior total cavopulmonary connection procedure
  • Obstruction of right atrial tunnel after prior total cavopulmonary connection procedure
  • Partial obstruction of cardiac conduit
  • Resistance on irrigation of totally implantable venous access device

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Complications of cardiac and vascular prosthetic devices, implants and grafts (T82). 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 INJ033
Complication of cardiovascular device, implant or graft, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert T82.598A to ICD-9-CMHistory

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

ICD-9-CM
996.09 Malfunc card dev/grf NEC
Approximate The match is approximate rather than exact.
ICD-9-CM
996.1 Malfunc vasc device/graf
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 T82.598AOverview

Is T82.598A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other mechanical complication of other cardiac and vascular devices and implants, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T82.598A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for other mechanical complication of other cardiac and vascular devices and implants, such as an emergency visit or first evaluation.

What MS-DRG does T82.598A group to?

When other mechanical complication of other cardiac and vascular devices and implants, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T82.598A a CC or MCC?

CMS lists T82.598A as a CC (complication or comorbidity) for FY 2026. 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 59 closely related codes in its exclusion list.

What is the ICD-9 equivalent of T82.598A?

Under the General Equivalence Mappings, other mechanical complication of other cardiac and vascular devices and implants, initial encounter converts to ICD-9-CM 996.09 (malfunc card dev/grf NEC) and 996.1 (malfunc vasc device/graf). The mapping is approximate, so confirm the match fits the documentation.

Does T82.598A risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. T82.598A 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).