Obstructive sleep apnea is increasingly recognized as a comorbidity in many medical illnesses. This has resulted in an increasing need for sleep testing, which is not entirely met by the currently available sleep laboratory facilities. Home, or out-of-center, sleep testing is an alternative to in-laboratory studies. However, coding and billing for home studies is not as straightforward as it is for in-laboratory studies. This article reviews the process of coding and billing for sleep studies done in an unattended setting.