Alphabetic Index FY2027

T85.191A

Other mechanical complication of implanted electronic neurostimulator of peripheral nerve electrode (lead), initial encounter

FY2027Chapter 19: Injury, poisoning and certain other consequences of external causes/T80–T88 Complications of surgical and medical care, not elsewhere classified

BillableComplete code, valid to report
Care settingsHome Health Primary · Neuro RehabilitationHospital CC

T85.191A (also written T85191A) is a billable ICD-10-CM diagnosis code for other mechanical complication of implanted electronic neurostimulator of peripheral nerve electrode (lead), initial encounter. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 288 codes in category T85 (Complications of other internal prosthetic devices, implants and grafts). The Alphabetic Index lists it under 5 entries. Its 7th character, A, means initial encounter. Its coding notes include a Use additional code instruction and 24 Excludes2 entries.

7th character

Category T85 requires a 7th character.

Assembled code T85.191A Open code

Guidelines tips

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

The 7th character depends on whether the patient is in active treatment, not on who sees the patient. An aftercare Z code is not used for injury aftercare.

Guidelines I.C.19.aInjuries: application of 7th charactersRead the official text

A complication code needs the provider's documented cause-and-effect link between the care and the condition. Some T codes already include the type of procedure, so no external cause code is needed.

Guidelines I.B.16; I.C.19.g.4Complications of careRead the official text

Use additional code

Add the listed code as a secondary code, if known.

Also from chapter/block level (4 notes)
Inherited from T80–T88 Complications of surgical and medical care, not elsewhere classified
  • 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)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • code to identify any retained foreign body, if applicable (Z18.-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Inherited from T85 Complications of other internal prosthetic devices, implants and grafts
  • failure and rejection of transplanted organs and tissue (T86.-)
Also from chapter/block level (23 notes)
Inherited from T80–T88 Complications of surgical and medical care, not elsewhere classified
  • 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:
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the Neuro Rehabilitation clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Hospital CC

Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 67 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.

Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix C

Inclusion terms

Conditions classified to this code.

Inherited from T85.191 Other mechanical complication of implanted electronic neurostimulator of peripheral nerve electrode
  • Other mechanical complication of electrode (lead) for cranial nerve neurostimulators
  • Other mechanical complication of electrode (lead) for gastric neurostimulator
  • Other mechanical complication of electrode (lead) for sacral nerve neurostimulator
  • Other mechanical complication of electrode (lead) for vagal nerve neurostimulators

Notes

Also from chapter/block level (2 notes)
Inherited from Chapter 19 Injury, poisoning and certain other consequences of external causes
  • 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.

Alphabetic Index terms

Terms the official Alphabetic Index lists for T85.191. This code adds the 7th character. 5 entries