2027 ICD-10-CM Diagnosis Code T88.6XXAAnaphylactic reaction due to adverse effect of correct drug or medicament properly administered, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T88

ICD-10-CM T88.6XXA
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T88.6XXA is a billable ICD-10-CM diagnosis code for anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, 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 915 through 916. 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 15 closely related codes. 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
T88.6XXA
Billable Status
Yes — Valid for Submission
Code Describes
Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, initial encounter
Short Description
Anaphyl reaction due to advrs eff drug/med prop admin, init
Parent Code
T88.6
Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT88Other complications of surgical and medical care, not elsewhere classified
This CodeT88.6XXAAnaphylactic reaction due to adverse effect of correct drug or medicament properly administered, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adverse reaction to platelet aggregation inhibitor
  • Adverse reaction to salicylate
  • Adverse reaction to whole blood
  • Allergic reaction after allergen immunotherapy
  • Allergic reaction caused by analgesic
  • Allergic reaction caused by anesthetic
  • Allergic reaction caused by antibacterial agent
  • Allergic reaction caused by antiinfective agent
  • Allergic reaction caused by nonsteroidal antiinflammatory agent
  • Allergic reaction caused by penicillin
  • Allergic reaction caused by sulfonamide
  • Allergic reaction to radiocontrast media
  • Anaphylaxis after allergen immunotherapy
  • Anaphylaxis caused by allergy skin test
  • Anaphylaxis caused by analgesic
  • Anaphylaxis caused by anesthetic
  • Anaphylaxis caused by antibacterial agent
  • Anaphylaxis caused by non-steroidal anti-inflammatory agent
  • Anaphylaxis caused by radiographic contrast media
  • Anaphylaxis caused by sulfonamide
  • Aspirin adverse reaction
  • Blood product-induced anaphylactoid reaction
  • Contrast media adverse reaction
  • Drug-induced anaphylaxis
  • Immediate transfusion reaction
  • Non-allergic anaphylaxis caused by aspirin
  • Non-allergic anaphylaxis caused by drug
  • Non-allergic anaphylaxis caused by non steroidal anti-inflammatory drug
  • Non-allergic anaphylaxis caused by parasympathomimetic agent
  • Non-allergic anaphylaxis caused by whole blood
  • Non-allergic hypersensitivity reaction caused by dialysis membrane
  • Non-allergic hypersensitivity reaction caused by radiocontrast media
  • Non-allergic hypersensitivity reaction during dialysis
  • Penicillin-induced anaphylaxis

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Other complications of surgical and medical care, not elsewhere classified (T88). 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 T88.6XXA: its own notes plus those printed at T88.6, T88, block T80-T88, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From T88.6 Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered applies to 3 codes
  • anaphylactic reaction due to serum (T80.5-)
  • anaphylactic shock or reaction due to adverse food reaction (T78.0-)

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 T88 Other complications of surgical and medical care, not elsewhere classified applies to 39 codes
  • complication following infusion, transfusion and therapeutic injection (T80.-)
  • complication following procedure NEC (T81.-)
  • complications of anesthesia in labor and delivery (O74.-)
  • complications of anesthesia in pregnancy (O29.-)
  • complications of anesthesia in puerperium (O89.-)
  • complications of devices, implants and grafts (T82-T85)
  • complications of obstetric surgery and procedure (O75.4)
  • dermatitis due to drugs and medicaments (L23.3, L24.4, L25.1, L27.0-L27.1)
  • poisoning and toxic effects of drugs and chemicals (T36-T65 with fifth or sixth character 1-4)
  • specified complications classified elsewhere
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 T88.6 Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered applies to 3 codes
  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
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 T88 Other complications of surgical and medical care, not elsewhere classified applies to 39 codes
  • The appropriate 7th character is to be added to each code from category T88
Values for category T88 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter this code
  • Dsubsequent encounter
  • Ssequela

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name T88.6XXA, its category, or a range that includes it.

Excludes1 5

These codes carry an Excludes1 note naming T88.6XXA: they are not reported together with it, unless the two conditions are unrelated.

  • R57 Shock, not elsewhere classified
    anaphylactic shock due to adverse effect of correct drug or medicament properly administered (T88.6) names T88.6, which includes this code
  • T78.2 Anaphylactic shock, unspecified
    anaphylactic reaction or shock due to adverse effect of correct medicinal substance properly administered (T88.6) names T88.6, which includes this code
  • T79.4 Traumatic shock
    anaphylactic shock due to correct medicinal substance properly administered (T88.6) names T88.6, which includes this code
  • T80.5 Anaphylactic reaction due to serum
    anaphylactic reaction or shock due to adverse effect of correct medicinal substance properly administered (T88.6) names T88.6, which includes this code
  • T81.1 Postprocedural shock
    anaphylactic shock due to correct substance properly administered (T88.6) names T88.6, which includes this code

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

Patient EducationClinical

Anaphylaxis

Anaphylaxis is a serious allergic reaction. It can begin very quickly, and symptoms may be life-threatening. The most common causes are reactions to foods (especially peanuts), medications, and stinging insects. Other causes include exercise and exposure to latex. Sometimes no cause can be found.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T88.6XXA to ICD-9-CMHistory

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

ICD-9-CM
995.0 Other anaphylactic react
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 T88.6XXAOverview

Is T88.6XXA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character A in T88.6XXA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, such as an emergency visit or first evaluation.

What MS-DRG does T88.6XXA group to?

When anaphylactic reaction due to adverse effect of correct drug or medicament properly administered, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 915, 916, with relative weights from 0.6926 to 1.6559 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T88.6XXA a CC or MCC?

CMS lists T88.6XXA 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 15 closely related codes in its exclusion list.

Can T88.6XXA be reported with a code from T80.5?

Not as a rule. The Excludes1 note at T88.6, which applies to T88.6XXA, lists "anaphylactic reaction due to serum (T80.5-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).