T78.40
Non-billableAllergy, unspecified
Allergy, unspecified
This is a header/category code. For billing purposes, use a more specific child code from the list below.
Coding Notes
Inclusion Terms
Alternative clinical terms for this condition
- Allergic reaction NOS
- Hypersensitivity NOS
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
- 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)
Excludes 2
Conditions not included here, but the patient may have both
- complications of surgical and medical care NEC (T80-T88)
Use Additional Code
Additional codes that should follow this code
- code to identify any retained foreign body, if applicable (Z18.-)
Child Codes (3)
Also Known As / Clinical Terms
UMLS
- Allergic ReactionC1527304
- Allergic ReactionsC1527304
- Allergic reactionC1527304
- Allergic reaction (disorder)C1527304
- Allergic reaction NOSC1527304
- Reaction allergic (NOS)C1527304
- Reaction, AllergicC1527304
- Reactions, AllergicC1527304
- Allergic disordersC0020517
- AllergiesC0020517
- AllergyC0020517
- Allergy NOSC0020517
- Allergy, unspecifiedC0020517
- HypersensitiveC0020517
- HypersensitivitiesC0020517
- HypersensitivityC0020517
- Hypersensitivity NOSC0020517
- Hypersensitivity reactionC0020517
- Hypersensitivity reaction (NOS)C0020517
- Hypersensitivity reaction (disorder)C0020517
- Hypersensitivity symptomC0020517
- Reaction hypersensitivity (NOS)C0020517
- SensitivityC0020517
- allergic disorderC0020517
- allergic disordersC0020517
- allergic reactionC0020517
- allergic reactionsC0020517
- allergiesC0020517
- allergyC0020517
- allergy disordersC0020517
- hypersensitivitiesC0020517
- hypersensitivityC0020517
- hypersensitivity reactionC0020517
- hypersensitivity reactionsC0020517
- hypersensitivity symptomC0020517
- hypersensitivity symptomsC0020517
Frequently Asked Questions
What is the ICD-10 code for allergy, unspecified?
The ICD-10-CM code for allergy, unspecified is T78.40. The full clinical description is "Allergy, unspecified". T78.40 is a non-billable header code. Use a more specific child code for billing purposes.
What does ICD-10 code T78.40 mean?
ICD-10-CM code T78.40 represents "Allergy, unspecified". It is classified under Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes and is a non-billable header code. Use a more specific child code for billing purposes.
Is T78.40 a billable code?
No, T78.40 is a non-billable header code. You need to use one of its more specific child codes for billing. There are 3 child codes under T78.40.
What chapter is T78.40 in?
T78.40 is in Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (codes S00-T88).
What codes cannot be used with T78.40?
T78.40 has Excludes1 notes indicating codes that cannot be used together with it, including: birth trauma (P10-P15); obstetric trauma (O70-O71); specified types of allergic reaction such as:; and 6 more.
What are the subcategories under T78.40?
T78.40 has 3 child codes, including: T78.40XA (Allergy, unspecified, initial encounter), T78.40XD (Allergy, unspecified, subsequent encounter), T78.40XS (Allergy, unspecified, sequela).
Are additional codes required with T78.40?
Yes, when using T78.40 you should also code: code to identify any retained foreign body, if applicable (Z18.-).
What are the UMLS CUIs for T78.40?
T78.40 is linked to 2 UMLS Concept Unique Identifiers: C1527304, C0020517. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.