E84 vs J42
E84 (Cystic fibrosis) compared with J42 (Unspecified chronic bronchitis), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. J42 carries an Excludes2 note covering E84: “cystic fibrosis (E84.-)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| E84Cystic fibrosis | J42Unspecified chronic bronchitis | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | E00-E89 — Endocrine, Nutritional and Metabolic Diseases (E00-E89) | J00-J99 — Diseases of the Respiratory System (J00-J99) |
| Definition | Cystic fibrosis is a non-billable ICD-10-CM category code (E84). | Unspecified chronic bronchitis is a billable ICD-10-CM diagnosis code (J42). |
| Includes | mucoviscidosis | Chronic bronchitis NOS Chronic tracheitis Chronic tracheobronchitis |
| Use additional code | — | code to identify: exposure to environmental tobacco smoke (Z77.22) exposure to tobacco smoke in the perinatal period (P96.81) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources