{"code":"I27.21","type":"code","title":"Secondary pulmonary arterial hypertension","codeAlso":["associated conditions if applicable, or adverse effects of drugs or toxins, such as:","adverse effect of appetite depressants (T50.5X5)","congenital heart disease (Q20-Q28)","human immunodeficiency virus [HIV] disease (B20)","polymyositis (M33.2-)","portal hypertension (K76.6)","rheumatoid arthritis (M05.-)","schistosomiasis (B65.-)","Sjögren syndrome (M35.0-)","systemic sclerosis (M34.-)","associated underlying condition"],"includes":[],"modern_v":"official26","codeFirst":[],"excludes1":["Eisenmenger's syndrome (I27.83)"],"excludes2":[],"isBillable":true,"fyEffectivity":{"fy2026":true,"fy2027":true,"billableFy2026":true,"billableFy2027":true},"sibling_codes":["I27","I27.0","I27.1","I27.2","I27.20","I27.22","I27.23","I27.24","I27.29","I27.8","I27.81","I27.82","I27.83","I27.84","I27.840","I27.841","I27.848","I27.849","I27.89","I27.9"],"inclusionTerms":["(Associated) (drug-induced) (toxin-induced) pulmonary arterial hypertension NOS","(Associated) (drug-induced) (toxin-induced) (secondary) group 1 pulmonary hypertension"],"sibling_titles":{"code":"I27.9","title":"Pulmonary heart disease, unspecified","isBillable":true},"useAdditionalCode":[],"clinicalDefinition":"Secondary pulmonary arterial hypertension is a billable ICD-10-CM diagnosis code (I27.21). Inclusion terms: (Associated) (drug-induced) (toxin-induced) pulmonary arterial hypertension NOS; (Associated) (drug-induced) (toxin-induced) (secondary) group 1 pulmonary hypertension. Excludes1 (not coded here): Eisenmenger's syndrome (I27.83). Code also: associated conditions if applicable, or adverse effects of drugs or toxins, such as:; adverse effect of appetite depressants (T50.","officialDefinition":"Secondary pulmonary arterial hypertension is a billable ICD-10-CM diagnosis code (I27.21). Inclusion terms: (Associated) (drug-induced) (toxin-induced) pulmonary arterial hypertension NOS; (Associated) (drug-induced) (toxin-induced) (secondary) group 1 pulmonary hypertension. Excludes1 (not coded here): Eisenmenger's syndrome (I27.83). Code also: associated conditions if applicable, or adverse effects of drugs or toxins, such as:; adverse effect of appetite depressants (T50.5X5); congenital heart disease (Q20-Q28); human immunodeficiency virus [HIV] disease (B20); polymyositis (M33.2-); portal hypertension (K76.6); rheumatoid arthritis (M05.-); schistosomiasis (B65.-); Sjögren syndrome (M35.0-); systemic sclerosis (M34.-); associated underlying condition.","seventhCharacterInstructions":[],"workflowProtocols":[],"guidelines":{"whenToUse":[],"whenNotToUse":[],"commonBillingMistakes":[],"codeComparisons":[],"documentationChecklist":[]},"domainLandscape":{"summary":"Primary diagnostic domain and clinical landscape evaluation.","keyCategories":[],"diagnosticContinuum":"Progression continuum from acute presentation to resolution."},"children":[],"hierarchy":[],"relatedCodes":[],"relevantCPTCodes":[],"documentationTips":[],"caseStudies":[],"description":"","overview":"","hcc":{"mapped":true,"model":"CMS-HCC V28","paymentYear":"2026","categories":[{"hcc":"226","label":"Heart Failure, Except End-Stage and Acute","family":"Heart","suppresses":[{"hcc":"227","label":"Cardiomyopathy/Myocarditis"}]}],"otherModels":[{"model":"CMS-HCC V22","hcc":"85"},{"model":"RxHCC V08","hcc":"183"}]}}