The actor, who played the lead role on 1970s U.S. TV show James at 15, was ordered to carry out 300 hours of community service and was given credit for time already served during sentencing last week (22Jul10).
Kerwin, who quit acting to become a pastor, was found guilty of faking documents to get state medical assistance and free food stamps - despite owning three homes.
He has repaid $21,822 (£14,000).
When sentenced to community service and placed on probation, he said, "I'm sorry. The last thing I want to do is to make a statement to minimise what I have done."