Injury, Poisoning and Certain Other Consequences of External Causes
ICD-10 Code: T50.905A
Adverse Effect of Unspecified Drugs, Medicaments and Biological Substances, Initial Encounter
Harmful reaction to medication taken as prescribed, drug unspecified, first visit.
Clinical Information
Harmful reaction to medication taken as prescribed, drug unspecified, first visit. Common in US healthcare settings with specific coding requirements per ICD-10-CM guidelines.
Coding Guidelines
- 1Use T50.905A when clinical documentation supports this diagnosis
- 2Verify specificity requirements per ICD-10-CM Official Guidelines
- 3Code to highest level of specificity documented
- 4Consider associated conditions and combination coding rules
Common Uses
- Primary diagnosis in ambulatory settings
- Secondary diagnosis in inpatient settings
- ED/urgent care encounters
- Follow-up and monitoring visits
Related ICD-10 Codes
T50.XRelated code in same category
See ICD-10-CM manualFor complete related code list
Documentation Requirements
- Physician documentation must clearly state diagnosis
- Include severity, laterality, and specificity when applicable
- Document underlying cause if known
- Note acute vs. chronic where relevant
Real-World Coding Examples
Patient presents with adverse effect of unspecified drugs, medicaments and biological substances, initial encounter. Clinical findings support T50.905A diagnosis.
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