The Supreme Court justices said they'll decide whether inmates have a constitutional right to jailhouse visits from young relatives and others.
The case will focus on whether the state of Michigan went too far when it banned visits by some children and former prisoners. The state also removed visitation privileges from inmates who used drugs.
Alabama is among nine other states to support Michigan.
Earlier this year, an appeals court sided with the inmates. It ruled that even if you're in prison, you still have a First Amendment right to associate with others.
Over the years, the Supreme Court has upheld restrictions on books, packages and visitors at prisons.