ICD-10-CM T78: Adverse effects, not elsewhere classified

ICD-10-CM Diagnosis Code (2025)

Official Description for T78

Adverse effects, not elsewhere classified

Coding Notes & Guidelines for T78

Excludes1: Not Coded Here
  • anaphylactic reaction or shock due to adverse food reaction (T78.0-)
  • anaphylactic reaction due to food (T78.0-)
  • bacterial food borne intoxications (A05.-)
Excludes1: Not Coded Here
  • anaphylactic reaction or shock due to adverse effect of correct medicinal substance properly administered (T88.6)
  • anaphylactic reaction or shock due to adverse food reaction (T78.0-)
  • anaphylactic reaction or shock due to serum (T80.5-)
Excludes1: Not Coded Here
  • serum urticaria (T80.6-)
  • urticaria (L50.-)
Excludes1: Not Coded Here
  • specified types of allergic reaction such as:
  • allergic diarrhea (K52.29)
  • allergic gastroenteritis and colitis (K52.29)
  • dermatitis (L23-L25, L27.-)
  • food protein-induced enterocolitis syndrome (K52.21)
  • food protein-induced enteropathy (K52.22)
  • hay fever (J30.1)
Excludes2: Not Included Here

complications of surgical and medical care NEC (T80-T88)

Excludes2: Not Included Here

anaphylactic reaction due to peanuts (T78.01)

Excludes2: Not Included Here
  • allergic and dietetic gastroenteritis and colitis (K52.29)
  • allergic rhinitis due to food (J30.5)
  • dermatitis due to food in contact with skin (L23.6, L24.6, L25.4)
  • dermatitis due to ingested food (L27.2)
  • food protein-induced enterocolitis syndrome (K52.21)
  • food protein-induced enteropathy (K52.22)
Use Additional Code

code to identify the type of reaction, if applicable

Inclusion Terms
  • Anaphylactic reaction due to adverse food reaction
  • Anaphylactic shock or reaction due to nonpoisonous foods
  • Anaphylactoid reaction due to food
Inclusion Terms
  • Allergic shock
  • Anaphylactic reaction
  • Anaphylaxis
Inclusion Terms
  • Allergic angioedema
  • Giant urticaria
  • Quincke's edema
Inclusion Terms
  • Allergic reaction NOS
  • Hypersensitivity NOS
Inclusion Terms

Arthus reaction

7th Character Guidance

The appropriate 7th character is to be added to each code from category T78

7th Character Definitions
  • A: initial encounter
  • D: subsequent encounter
  • S: sequela

Child Codes (More Specific Codes for T78):

T78.0 - Anaphylactic reaction due to food T78.00 - Anaphylactic reaction due to unspecified food T78.01 - Anaphylactic reaction due to peanuts T78.02 - Anaphylactic reaction due to shellfish (crustaceans) T78.03 - Anaphylactic reaction due to other fish T78.04 - Anaphylactic reaction due to fruits and vegetables T78.05 - Anaphylactic reaction due to tree nuts and seeds T78.06 - Anaphylactic reaction due to food additives T78.07 - Anaphylactic reaction due to milk and dairy products T78.08 - Anaphylactic reaction due to eggs T78.09 - Anaphylactic reaction due to other food products T78.1 - Other adverse food reactions, not elsewhere classified T78.2 - Anaphylactic shock, unspecified T78.3 - Angioneurotic edema T78.4 - Other and unspecified allergy T78.40 - Allergy, unspecified T78.41 - Arthus phenomenon T78.49 - Other allergy T78.8 - Other adverse effects, not elsewhere classified

About ICD-10-CM Code T78 (Adverse effects)

ICD-10-CM code T78 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM T78 became effective on October 1, 2024.

This page provides detailed information about T78 - Adverse effects, not elsewhere classified. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Adverse effects related to not elsewhere classified.