2027 ICD-10-CM Diagnosis Code T85.09XAOther mechanical complication of ventricular intracranial (communicating) shunt, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T85

ICD-10-CM T85.09XA
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T85.09XA is a billable ICD-10-CM diagnosis code for other mechanical complication of ventricular intracranial (communicating) shunt, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 91 through 93. 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 67 closely related codes. Coders also document this condition as brain ventricular shunt malfunction. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of other surgical or medical care, injury, initial encounter.

T85.09XA 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
T85.09XA
Billable Status
Yes — Valid for Submission
Code Describes
Other mechanical complication of ventricular intracranial (communicating) shunt, initial encounter
Short Description
Mech compl of ventricular intracranial shunt, init
Parent Code
T85.09
Other mechanical complication of ventricular intracranial (communicating) shunt

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 CodeT85.09XAOther mechanical complication of ventricular intracranial (communicating) shunt, initial encounter

Medicare Risk Adjustment (HCC)Billing

T85.09XA 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
T85.09XA 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.

  • Brain ventricular shunt malfunction
  • Brain ventricular shunt obstruction
  • Cranial cerebrospinal fluid leak
  • Disorder of brain ventricular shunt
  • Leak of cranial cerebrospinal fluid due to under-drainage of ventricular shunt
  • Ventriculoperitoneal shunt malfunction

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 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 T85.09XA: its own notes plus those printed at T85, 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 T85 Complications of other internal prosthetic devices, implants and grafts applies to 288 codes
  • failure and rejection of transplanted organs and tissue (T86.-)
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 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.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From T85 Complications of other internal prosthetic devices, implants and grafts applies to 288 codes
  • The appropriate 7th character is to be added to each code from category T85
Values for category T85 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

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

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 T85.09XA to ICD-9-CMHistory

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

ICD-9-CM
996.2 Malfun neuro 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T85.09XAOverview

Is T85.09XA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other mechanical complication of ventricular intracranial (communicating) shunt, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in T85.09XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for other mechanical complication of ventricular intracranial (communicating) shunt, such as an emergency visit or first evaluation.

What MS-DRG does T85.09XA group to?

When other mechanical complication of ventricular intracranial (communicating) shunt, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 91, 92, 93, with relative weights from 0.7783 to 1.7050 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T85.09XA a CC or MCC?

CMS lists T85.09XA 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 67 closely related codes in its exclusion list.

What is the ICD-9 equivalent of T85.09XA?

Under the General Equivalence Mappings, other mechanical complication of ventricular intracranial (communicating) shunt, initial encounter converts to ICD-9-CM 996.2 (malfun neuro device/graf). The mapping is approximate, so confirm the match fits the documentation.

Does T85.09XA risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. T85.09XA 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).