In Janus v. AFSCME, Counsel 31, the U.S. Supreme Court ruled that it is unconstitutional for a State or labor union to require public-sector employees who are not union members to pay fees to the union. 

The plaintiff, Mark Janus, a state employee, argued that an Illinois law requiring him to pay such fees to the union without his consent violated his free speech rights under the First Amendment.  The Supreme Court agreed, holding, in part, that public-sector collective bargaining involves critically important and public matters, such as the State’s budget crisis, taxes, education, child welfare, healthcare, and minority rights. 

After Janus, public-sector employers are not allowed to withhold union fees from the paychecks of public employees who are not union members.