OBJECTIVE St Louis Children's Hospital (SLCH) developed Service for Hospital Admissions by Referring Physicians (SHARP) in January 2008 as an inpatient referral service for pediatricians who previously admitted their own patients. We hypothesized that use of SHARP would make hospitalization more efficient and cost-effective compared with the general pediatric medicine (GM) service. METHODS Admission volumes, diagnoses, length of stay (LOS), costs, and physician billing data were abstracted from SLCH information systems and the Pediatric Health Information System database. We compared admissions for SHARP and GM from January 2008 through June 2010. RESULTS SHARP had lower LOS and costs versus GM, with no change in 7-day readmission rate. Median LOS was 2 days for SHARP and 3 days for GM (P<.001). Median hospital cost per patient was $2719 for SHARP and $3062 for GM (P<.001). Over the study period, the admission rate increased 37% and daily patient encounters increased 39%. Physician billing revenue increased 25% in the first 6 months, then continued to increase steadily. Total physicians and geographic referral area using SHARP increased, and referring physician satisfaction was high. CONCLUSIONS SHARP approaches financial independence and provides a cost savings to SLCH. LOS decreased by a statistically significant amount compared with GM with no change in readmission rate. Referring physician satisfaction was high, likely allowing for growth in referrals to SLCH. SHARP hospitalists' collaboration with referring physicians, ensuring excellent follow-up, provides decreased duration of hospitalization and resource utilization. Our availability throughout the day to reassess patients increases efficiency. We project that we must average 12.6 daily encounters to be financially independent.