To assess the role of neonatal pulse oximetry screening and other bases of referral for patients of all ages with aortic coarctation referred to a tertiary care medical center. Medical records were reviewed for 200 consecutive patients diagnosed and treated for CoA in either 2006-2011 or 2015-2019, before and after mandated pulse oximetry screening, respectively. In both groups, ∼50% of patients were diagnosed within the first 5days. Diagnosis by fetal echocardiography was more frequent in the 2015-2019 group (30.5% vs 20.5%; P<.03); obstruction often developed only as the ductus arteriosus closed. In each group, ∼25% of patients were diagnosed at age >1year and 7% had an incidental diagnosis. Pulse oximetry screening was documented as abnormal in only 8 of 47 patients and was not performed in those with a fetal diagnosis. Evaluation of a murmur was the second most frequent basis for referral. Moderate to severe left ventricular dysfunction occurred mainly in infants in the first month, with a similar frequency in the 2 groups; these patients often had tachypnea or poor weight gain. Decreased femoral pulses or systemic hypertension were infrequently documented by referring physicians. Hypertension typically was ascribed to a renal or essential basis. Exercise symptoms occurred mainly in patients age >10years. Although fetal echocardiography and neonatal pulse oximetry contribute to the diagnosis of coarctation, physical examination has an important complementary role. Evaluation of peripheral pulses on initial and early follow-up neonatal examinations, along with consideration of coarctation in any patient with hypertension, are needed to improve timely detection.