ICD-10-CM Codes
S00-T88 Injury, poisoning and certain other consequences of external causes
T66-T78 Other and unspecified effects of external causes
T78- Adverse effects, not elsewhere classified

2020 ICD-10-CM Diagnosis Code T78.40XA

Allergy, unspecified, initial encounter

2016

2017

2018

2019

2020

Billable/Specific Code

T78.40XA is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
The 2020 edition of ICD-10-CM T78.40XA became effective on October 1, 2019.
This is the American ICD-10-CM version of T78.40XA - other international versions of ICD-10 T78.40XA may differ.

The following code(s) above T78.40XA contain annotation back-references

Annotation Back-References

In this context, annotation back-references refer to codes that contain:

Applicable To annotations, or
Code Also annotations, or
Code First annotations, or
Excludes1 annotations, or
Excludes2 annotations, or
Includes annotations, or
Note annotations, or
Use Additional annotations

that may be applicable to T78.40XA:

S00-T88
2020 ICD-10-CM Range S00-T88
Injury, poisoning and certain other consequences of external causes
Note
- 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
Type 1 Excludes
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Use Additional
- code to identify any retained foreign body, if applicable (Z18.-)
Injury, poisoning and certain other consequences of external causes
T78
ICD-10-CM Diagnosis Code T78
Adverse effects, not elsewhere classified
Type 2 Excludes
- complications of surgical and medical care NEC (T80-T88)
Adverse effects, not elsewhere classified
T78.4
ICD-10-CM Diagnosis Code T78.4
Other and unspecified allergy
Type 1 Excludes
- 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)
Other and unspecified allergy
T78.40
ICD-10-CM Diagnosis Code T78.40
Allergy, unspecified
Applicable To
- Allergic reaction NOS
- Hypersensitivity NOS
Allergy, unspecified

Approximate Synonyms

Allergic condition
Allergic disorder
Allergic disposition
Allergic reaction
Allergy
Hypersensitivity reaction
Immune hypersensitivity reaction
Non-celiac gluten sensitivity
Oral allergy syndrome
Pollen-food allergy

ICD-10-CM T78.40XA is grouped within Diagnostic Related Group(s) (MS-DRG v37.0):

915 Allergic reactions with mcc
916 Allergic reactions without mcc

Convert T78.40XA to ICD-9-CM

Code History

2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
2017 (effective 10/1/2016): No change
2018 (effective 10/1/2017): No change
2019 (effective 10/1/2018): No change
2020 (effective 10/1/2019): No change

ICD-10-CM Codes Adjacent To T78.40XA

T78.2 Anaphylactic shock, unspecified

T78.2XXA …… initial encounter

T78.2XXD …… subsequent encounter

T78.2XXS …… sequela

T78.3 Angioneurotic edema

T78.3XXA …… initial encounter

T78.3XXD …… subsequent encounter

T78.3XXS …… sequela

T78.4 Other and unspecified allergy

T78.40 Allergy, unspecified

T78.40XA …… initial encounter

T78.40XD …… subsequent encounter

T78.40XS …… sequela

T78.41 Arthus phenomenon

T78.41XA …… initial encounter

T78.41XD …… subsequent encounter

T78.41XS …… sequela

T78.49 Other allergy

T78.49XA …… initial encounter

T78.49XD …… subsequent encounter

T78.49XS …… sequela

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.

2020 ICD-10-CM Diagnosis Code T78.40XA

Allergy, unspecified, initial encounter

Injury, poisoning and certain other consequences of external causes

Adverse effects, not elsewhere classified

Other and unspecified allergy

Allergy, unspecified