The federal government is imposing a cap of 15 days on holding prisoners in solitary confinement.
Once the bill tabled in the House of Commons Monday passes into law, the Correctional Service of Canada will have an 18-month transition period, during which time the cap will be set at 21 days.
The time limits are subject to safety and security requirements, as well as ensuring reasonable alternatives are available.
There will be an independent review process if the cap is not met, or if an inmate is placed in segregation more than four times in a 90-day period.
Monday's announcement comes just weeks before a lawsuit challenging the practice of solitary confinement was scheduled to go to trial on July 4. The British Columbia Civil Liberties Association, which launched the legal action, is not commenting because the case is set to begin.