2027 ICD-10-CM Diagnosis Code T85.510ABreakdown (mechanical) of bile duct prosthesis, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T85

ICD-10-CM T85.510A
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T85.510A is a billable ICD-10-CM diagnosis code for breakdown (mechanical) of bile duct prosthesis, 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 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 58 closely related codes. Coders also document this condition as disorder of bile duct prosthesis. 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
T85.510A
Billable Status
Yes — Valid for Submission
Code Describes
Breakdown (mechanical) of bile duct prosthesis, initial encounter
Short Description
Breakdown (mechanical) of bile duct prosthesis, init encntr
Parent Code
T85.510
Breakdown (mechanical) of bile duct prosthesis

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 CodeT85.510ABreakdown (mechanical) of bile duct prosthesis, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of bile duct prosthesis
  • Malfunction of bile duct prosthesis

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 T85.510A: 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 T85.510A to ICD-9-CMHistory

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

ICD-9-CM
996.59 Malfunc oth device/graft
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 T85.510AOverview

What is the ICD-10 code for breakdown (mechanical) of bile duct prosthesis, initial encounter?

The ICD-10-CM code for breakdown (mechanical) of bile duct prosthesis, initial encounter is T85.510A (sometimes written as T85510A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T85.510A (Breakdown (mechanical) of bile duct prosthesis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report breakdown (mechanical) of bile duct prosthesis, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in T85.510A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for breakdown (mechanical) of bile duct prosthesis, such as an emergency visit or first evaluation.

What MS-DRG does T85.510A group to?

When breakdown (mechanical) of bile duct prosthesis, initial encounter 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 T85.510A a CC or MCC?

CMS lists T85.510A 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 58 closely related codes in its exclusion list.