A low socioeconomic status (SES) has been linked to disproportionate access to health care in many diseases, leading to worse disease severity at initial presentation. There is a paucity of these data in the pulmonary hypertension (PHTN) population. We studied the association of SES, as measured by zip code–based median annual household income, with World Health Organization functional class (WHO-FC) at time of first evaluation in PHTN patients. All patients evaluated at our center with a right heart catheterization revealing a mean pulmonary artery pressure of ≥25 mmHg within 12 months of initial evaluation were considered for the study. Demographics, WHO-FC, and zip codes were obtained from retrospective chart analysis. The 2010 US census was used to obtain zip code–based annual median income. The income groups were divided into quartiles. Patients were categorized by their WHO-FC and zip code–derived median income. Similar analyses were conducted for pulmonary arterial hypertension (PAH) patients. Survival was estimated with the Kaplan-Meier method. Data were analyzed in SAS, and P < 0.05 was considered significant. There were 228 PHTN patients (70 [30.7%] male, 158 [69.3%] female). As median income decreased, the FC at presentation increased, signifying higher disease severity (Spearman correlation: r = −0.161, P < 0.0515). This association between median income groups and WHO-FC at initial evaluation was significant (χ2 test: P < 0.0168). There were 116 PAH patients (32 [27.6%] male, 84 [72.4%] female). There was again a negative relationship between income and initial FC (Spearman correlation: r = −0.0307, P < 0.0007). A lower SES was associated with worse disease, as measured by WHO-FC.