Bonsall pleaded guilty Thursday in Boulder to felony menacing and third-degree assault.
The menacing charge won't appear on his record, if he stays out of trouble for two years.
The 28-year-old also pleaded guilty Thursday to violating terms of his probation stemming from a 2007 assault on his girlfriend and was sentenced to five days in a work-release program and 40 hours of community service. Bonsall had tested positive for marijuana.
His attorney told a judge Bonsall has substance abuse issues.
Bonsall played the youngest son on "Family Ties," starring Michael J. Fox.