E03.1 vs E03.4
E03.1 and E03.4 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter. The distinction is congenital vs acquired.
The official note, declared on E03.4
congenital atrophy of thyroid (E03.1)
E03.1
Congenital hypothyroidism without goiter
Billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E00-E07
Use when the record says
- Aplasia of thyroid (with myxedema)
- Congenital atrophy of thyroid
- Congenital hypothyroidism NOS
Indexed under
- Agenesis › thyroid
- Aplasia › thyroid
- Athyrea › congenital (acquired)
- Hypoplasia, hypoplastic › thyroid
- Hypothyroidism › congenital (acquired)
E03.4
Atrophy of thyroid (acquired)
Billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E00-E07
Indexed under
- Gull's disease
- Strumipriva cachexia
- Atrophy, atrophic › thyroid (of)
- Cachexia › strumipriva
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027