2026 ICD-10-CM Diagnosis Code T78.119D
Other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity, unspecified, subsequent encounter
- ICD-10-CM Code:
- T78.119D
- ICD-10 Code for:
- Oth ad rct d/t milk /dair prod w bkd milk tol/rct,unsp,subs
- Is Billable?
- Yes - Valid for Submission
- Code Navigator:
T78.119D is a billable diagnosis code used to specify a medical diagnosis of other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity, unspecified, subsequent encounter. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.
This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.
T78.119D is a subsequent encounter code, includes a 7th character and should be used after the patient has completed active treatment for a condition like other adverse food reaction due to milk and dairy products with baked milk tolerance/reactivity unspecified. According to ICD-10-CM Guidelines a "subsequent encounter" occurs when the patient is receiving routine care for the condition during the healing or recovery phase of treatment. Subsequent diagnosis codes are appropriate during the recovery phase, no matter how many times the patient has seen the provider for this condition. If the provider needs to adjust the patient's care plan due to a setback or other complication, the encounter becomes active again.
Unspecified diagnosis codes like T78.119D are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.
Coding Guidelines
The appropriate 7th character is to be added to each code from block Adverse effects, not elsewhere classified (T78). Use the following options for the aplicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
New 2026 ICD-10-CM Code
T78.119D is new to ICD-10-CM code set for the FY 2026, effective October 1, 2025. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2025. This is a new and revised code for the FY 2026 (October 1, 2025 - September 30, 2026).
Code Edits
The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.
Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.
Present on Admission (POA)
T78.119D is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.
CMS POA Indicator Options and Definitions
POA Indicator: Y
Reason: Diagnosis was present at time of inpatient admission.
CMS Pays CC/MCC DRG? YES
POA Indicator: N
Reason: Diagnosis was not present at time of inpatient admission.
CMS Pays CC/MCC DRG? NO
POA Indicator: U
Reason: Documentation insufficient to determine if the condition was present at the time of inpatient admission.
CMS Pays CC/MCC DRG? NO
POA Indicator: W
Reason: Clinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.
CMS Pays CC/MCC DRG? YES
POA Indicator: 1
Reason: Unreported/Not used - Exempt from POA reporting.
CMS Pays CC/MCC DRG? NO
Replacement Code
T78119D replaces the following previously assigned ICD-10-CM code(s):
- T78.1XXD - Oth adverse food reactions, not elsewhere classified, subs
Code History
- FY 2026 - Code Added, effective from 10/1/2025 through 9/30/2026
