I27.0 vs I27.21
I27.0 (Primary pulmonary hypertension) compared with I27.21 (Secondary pulmonary arterial hypertension), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. I27.0 carries an Excludes1 note covering I27.21: “secondary pulmonary arterial hypertension (I27.21)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| I27.0Primary pulmonary hypertension | I27.21Secondary pulmonary arterial hypertension | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | I00-I99 — Diseases of the Circulatory System (I00-I99) | I00-I99 — Diseases of the Circulatory System (I00-I99) |
| Definition | Primary pulmonary hypertension is a billable ICD-10-CM diagnosis code (I27.0). | Secondary pulmonary arterial hypertension is a billable ICD-10-CM diagnosis code (I27.21). |
| Includes | Heritable pulmonary arterial hypertension Idiopathic pulmonary arterial hypertension Primary group 1 pulmonary hypertension Primary pulmonary arterial hypertension | (Associated) (drug-induced) (toxin-induced) pulmonary arterial hypertension NOS (Associated) (drug-induced) (toxin-induced) (secondary) group 1 pulmonary hypertension |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources