Of the 2,963,000 adults on probation in the US at the end of 2021, 16% (approximately 474,080 people) had a drug charge as their most serious offense. The most serious offense was unknown for 38% of the total (approximately 1,125,940 people).
Source
Danielle Kaeble. Probation and Parole in the United States, 2021. February 2023. NCJ 305589. Washington, DC: Bureau of Justice Statistics.
