Zolpidem was approved for medical use in the United States in 1992. It became available as a generic medication in 2007. In the United States, it has a monthly cost of about US$8 for immediate release and US$66 for controlled release medication, as of 2017. Zolpidem is a Schedule IV controlled substance under the Controlled Substances Act of 1970 (CSA). More than 10 million prescriptions are filled a year in the United States, making it one of the most commonly used treatments for sleeping problems.