The changing health care system has reduced patients' access to specialty care. Often, patients with hypertension visit noncardiologists. The objective of this study is to compare differences by physician specialty in the provision of health care services during office visits for hypertension. The authors examined office visits for US physicians by using data from the National Ambulatory Medical Care Survey for 2003 to 2005. Of more than 274 million hypertension visits, 35.5%, 43.9%, 8.5%, and 12.1% visits were made to general practitioners/family physicians, internists, cardiologists, and other specialties, respectively. Visitors to cardiologists were more likely to have coronary heart disease and heart failure than visitors to other physicians. While prescriptions for antihypertensive drugs overall were similar by specialty, cardiologists were more likely to prescribe lipid-lowering drugs (odds ratio [OR], 1.60; 95% confidence interval [CI], 1.14-2.24) and aspirin (OR, 2.76; 95% CI, 1.81-4.20), calcium channel blockers (OR, 1.48; 95% CI, 1.12-1.96), beta-blockers (OR, 1.83; 95% CI, 1.35-2.48), and alpha-blockers (OR, 2.10; 95% CI, 1.46-2.95) than general practitioners/family physicians after adjusting for relevant risk factors. There was no difference by specialty in providing/making a referral for nutrition/exercise counseling among physicians. Among hypertension office visits in the United States, cardiologists were more likely to provide lipid-lowering drugs, aspirin, calcium channel blocker, beta-blockers, and alpha-blockers than other physicians.