Acromegaly is a chronic disorder characterized by excess growth hormone secretion and elevated insulin-like growth factor-1 levels most often caused by a pituitary adenoma. Clinical presentation of the disease includes coarsening of the facial features, soft-tissue swelling of the hands and feet, and overgrowth of the frontal skull and protrusion of the jaw, as well as joint symptoms. Acromegaly is associated with several comorbidities, including diabetes, cardiovascular disease, and arthropathy, which, if left untreated, can lead to early mortality. Surgery to remove the adenoma is the first-line treatment for many patients, but more than 50% of patients will require additional pharmacologic or radiation therapy. To (a) determine the clinical and economic burden of illness among patients with acromegaly using administrative claims data from a large, commercially insured population in the United States and (b) estimate the most frequent acromegaly-related comorbidities and health care resource utilization and costs among these patients. This retrospective, observational cohort study used administrative claims data from the HealthCore Integrated Research Database, containing a geographically diverse spectrum of longitudinal claims data from the largest database of commercially insured patients in the United States. Patients were aged ≥ 20 years and fulfilled ≥ 1 of the following criteria during the intake period (March 31, 2008-July 31, 2012): ≥ 2 independent diagnostic codes for acromegaly, ≥ 1 acromegaly diagnosis code and ≥ 1 acromegaly-related procedure code, or ≥ 1 acromegaly diagnosis code and ≥ 1 medical claim for acromegaly-related therapy. The index date was defined as the date of the first medical claim for acromegaly within the intake period. Assessed outcomes included prevalence of acromegaly diagnosis and incidence of new acromegaly diagnoses during the study period (January 1, 2008-July 31, 2013), acromegaly-related comorbidities, and pharmacotherapy use. Because 2008 and 2012 data were incomplete, incidence rates were only reported for 2009, 2010, and 2011. Total and acromegaly-related health care resource utilization and annual health care costs were analyzed during a 12-month post-index observational period. In total, 757 patients with acromegaly met the selection criteria for this study, with a mean age of 49.3 years (53.6% female). The total prevalence of acromegaly was 41.7 cases per million. Acromegaly incidence was 15.0, 13.3, and 9.5 cases per million in 2009, 2010, and 2011, respectively. The top 5 acromegaly-related comorbidities were hypertension, diabetes, hypothyroidism, arthropathy/arthralgia/synovitis, and sleep apnea. During the study period, 51% of patients (n = 385) used acromegaly-related pharmacologic therapy, with the most common being cabergoline and octreotide (used by 12.4% and 12.2% of patients, respectively). Overall, 18.8% of patients incurred an acromegaly-related inpatient stay; 97.0% used outpatient services other than emergency room (ER) or physician visits; 74.8% had a physician office visit; and 1.8% visited the ER for acromegaly-related reasons. In the 12-month post-index period, 37.0% of patients filed claims for acromegaly-related prescription drugs, and patients with greater than 1 claim had an average of 7.6 prescriptions. The most expensive acromegaly-related costs in this study population were inpatient hospitalizations ($6,754) and prescription drugs ($6,147). Consistent with previous studies, this study confirms that acromegaly is a rare condition associated with multiple comorbidities. Notably, 18.8% of this study population required an inpatient hospital admission during the 12-month post-index period, possibly because of severe comorbidities. Because acromegaly-related costs were driven by hospitalizations and pharmacotherapy, improved management of the disease may reduce the clinical and economic burden experienced by patients with acromegaly.