ICD-10 Code for Allergy
Also indexed as (reaction) (to)
The ICD-10-CM code for allergy is T78.40 — Allergy, unspecified. This is the code the Alphabetic Index gives for allergy with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
Not billable
T78.40 cannot be submitted on a claim. It is a header code, so a more specific code from the list below is required.
Which allergy code should you use?
The Alphabetic Index lists 57 codes under Allergy, allergic. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| air-borne substance NEC | J30.89 | Other allergic rhinitis |
| alveolitis | J67.9 | Hypersensitivity pneumonitis due to unspecified organic dust |
| anaphylactic reaction or shock | T78.2Not billable | Anaphylactic shock, unspecified |
| angioneurotic edema | T78.3Not billable | Angioneurotic edema |
| animal | J30.81 | Allergic rhinitis due to animal (cat) (dog) hair and dander |
| bee sting | T63.44Not billable | Toxic effect of venom of bees |
| colitis | K52.29 | Other allergic and dietetic gastroenteritis and colitis |
| dairy products | T78.119Not billable | Other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity, unspecified |
| dander | J30.81 | Allergic rhinitis due to animal (cat) (dog) hair and dander |
| dandruff | J30.81 | Allergic rhinitis due to animal (cat) (dog) hair and dander |
| dental restorative material | K08.55 | Allergy to existing dental restorative material |
| drug, medicament & biological | T78.40Not billable | Allergy, unspecified |
| due to pollen | J30.1 | Allergic rhinitis due to pollen |
| dust | J30.89 | Other allergic rhinitis |
| epidermal | J30.81 | Allergic rhinitis due to animal (cat) (dog) hair and dander |
| feathers | J30.89 | Other allergic rhinitis |
| food NEC | T78.19Not billable | Other adverse food reactions, not elsewhere classified |
| grain | J30.1 | Allergic rhinitis due to pollen |
| grass | J30.1 | Allergic rhinitis due to pollen |
| hair | J30.81 | Allergic rhinitis due to animal (cat) (dog) hair and dander |
| inhalant | J30.89 | Other allergic rhinitis |
| kapok | J30.89 | Other allergic rhinitis |
| milk protein | Z91.0110 | Allergy to milk products, unspecified |
| nasal, seasonal due to pollen | J30.1 | Allergic rhinitis due to pollen |
| pneumonia | J82.89 | Other pulmonary eosinophilia, not elsewhere classified |
| pollen | J30.1 | Allergic rhinitis due to pollen |
| primrose | J30.1 | Allergic rhinitis due to pollen |
| primula | J30.1 | Allergic rhinitis due to pollen |
| proctocolitis | K52.29 | Other allergic and dietetic gastroenteritis and colitis |
| purpura | D69.0 | Allergic purpura |
| ragweed | J30.1 | Allergic rhinitis due to pollen |
| rose | J30.1 | Allergic rhinitis due to pollen |
| seasonal NEC | J30.2 | Other seasonal allergic rhinitis |
| Senecio jacobae | J30.1 | Allergic rhinitis due to pollen |
| serum | T80.69Not billable | Other serum reaction due to other serum |
| shock | T78.2Not billable | Anaphylactic shock, unspecified |
| specific NEC | T78.49Not billable | Other allergy |
| tree | J30.1 | Allergic rhinitis due to pollen |
| upper respiratory | J30.9 | Allergic rhinitis, unspecified |
| urticaria | L50.0 | Allergic urticaria |
Allergy alveolitis
Allergy dairy products
| anaphylactic reaction | T78.079Not billable | Anaphylactic reaction due to milk and dairy products, unspecified |
| with › reactivity to baked milk | T78.111Not billable | Other adverse food reaction due to milk and dairy products with reactivity to baked milk |
| with › tolerance to baked milk | T78.110Not billable | Other adverse food reactions due to milk and dairy products with tolerance to baked milk |
| anaphylactic reaction › with › reactivity to baked milk | T78.071Not billable | Anaphylactic reaction due to milk and dairy products with reactivity to baked milk |
| anaphylactic reaction › with › tolerance to baked milk | T78.070Not billable | Anaphylactic reaction due to milk and dairy products with tolerance to baked milk |
Allergy eggs
| adverse reaction NEC | T78.129Not billable | Other adverse food reaction due to egg with baked egg tolerance/reactivity, unspecified |
| anaphylactic reaction | T78.089Not billable | Anaphylactic reaction due to eggs, unspecified |
| adverse reaction NEC › with › reactivity to baked egg | T78.121Not billable | Other adverse food reaction due to egg with reactivity to baked egg |
| adverse reaction NEC › with › tolerance to baked egg | T78.120Not billable | Other adverse food reaction due to egg with tolerance to baked egg |
| anaphylactic reaction › with › reactivity to baked egg | T78.081Not billable | Anaphylactic reaction due to egg with reactivity to baked egg |
| anaphylactic reaction › with › tolerance to baked egg | T78.080Not billable | Anaphylactic reaction due to egg with tolerance to baked egg |
Allergy food NEC
| dietary counseling and surveillance | Z71.3 | Dietary counseling and surveillance |
| in contact with skin | L23.6 | Allergic contact dermatitis due to food in contact with the skin |
| rhinitis | J30.5 | Allergic rhinitis due to food |
| status | Z91.018 | Allergy to other foods |
| status › beef | Z91.014 | Allergy to mammalian meats |
| status › eggs | Z91.0120 | Allergy to eggs, unspecified |
| status › lamb | Z91.014 | Allergy to mammalian meats |
| status › mammalian meats | Z91.014 | Allergy to mammalian meats |
| status › milk products | Z91.0110 | Allergy to milk products, unspecified |
| status › peanuts | Z91.010 | Allergy to peanuts |
| status › pork | Z91.014 | Allergy to mammalian meats |
| status › red meats | Z91.014 | Allergy to mammalian meats |
| status › seafood | Z91.013 | Allergy to seafood |
| status › specified NEC | Z91.018 | Allergy to other foods |
| status › eggs › with › reactivity to baked egg | Z91.0122 | Allergy to eggs with reactivity to baked egg |
| status › eggs › with › tolerance to baked egg | Z91.0121 | Allergy to eggs with tolerance to baked egg |
| status › milk products › with › reactivity to baked milk | Z91.0112 | Allergy to milk products with reactivity to baked milk |
| status › milk products › with › tolerance to baked milk | Z91.0111 | Allergy to milk products with tolerance to baked milk |
Allergy gastrointestinal
Allergy inhalant
| pollen | J30.1 | Allergic rhinitis due to pollen |
Allergy milk protein
| adverse reaction NEC | T78.119Not billable | Other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity, unspecified |
| anaphylactic reaction | T78.079Not billable | Anaphylactic reaction due to milk and dairy products, unspecified |
| dermatitis | L27.2 | Dermatitis due to ingested food |
| enterocolitis syndrome | K52.21 | Food protein-induced enterocolitis syndrome |
| enteropathy | K52.22 | Food protein-induced enteropathy |
| gastroenteritis | K52.29 | Other allergic and dietetic gastroenteritis and colitis |
| gastroesophageal reflux | K21.9 | Gastro-esophageal reflux disease without esophagitis |
| proctocolitis | K52.29 | Other allergic and dietetic gastroenteritis and colitis |
| with › reactivity to baked milk | Z91.0112 | Allergy to milk products with reactivity to baked milk |
| with › tolerance to baked milk | Z91.0111 | Allergy to milk products with tolerance to baked milk |
| gastroesophageal reflux › with esophagitis | K21.00 | Gastro-esophageal reflux disease with esophagitis, without bleeding |
| adverse reaction NEC › with › reactivity to baked milk | T78.111Not billable | Other adverse food reaction due to milk and dairy products with reactivity to baked milk |
| adverse reaction NEC › with › tolerance to baked milk | T78.110Not billable | Other adverse food reactions due to milk and dairy products with tolerance to baked milk |
| anaphylactic reaction › with › reactivity to baked milk | T78.071Not billable | Anaphylactic reaction due to milk and dairy products with reactivity to baked milk |
| anaphylactic reaction › with › tolerance to baked milk | T78.070Not billable | Anaphylactic reaction due to milk and dairy products with tolerance to baked milk |
| gastroesophageal reflux › with esophagitis › with bleeding | K21.01 | Gastro-esophageal reflux disease with esophagitis, with bleeding |
Allergy serum
| anaphylactic shock | T80.59Not billable | Anaphylactic reaction due to other serum |
Allergy shock
| due to › administration of blood and blood products | T80.51Not billable | Anaphylactic reaction due to administration of blood and blood products |
| due to › adverse effect of correct medicinal substance properly administered | T88.6Not billable | Anaphylactic reaction due to adverse effect of correct drug or medicament properly administered |
| due to › immunization | T80.52Not billable | Anaphylactic reaction due to vaccination |
| due to › serum NEC | T80.59Not billable | Anaphylactic reaction due to other serum |
| due to › vaccination | T80.52Not billable | Anaphylactic reaction due to vaccination |
Codes under T78.40
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources