Members of Congress and civil rights groups are pushing the Federal Communications Commission to rein in telephone companies that, in many states, charge inmates spectacularly high rates that can force their families to choose between keeping in touch with a relative behind bars and, in some cases, putting food on the table.

The time is long past for the F.C.C. — which has been weighing this issue for nearly a decade — to break up what amount to monopolies and ensure that prisoners across the country have access to reasonably priced interstate telephone service.

The calls are expensive because they are placed through independent telephone companies that pay the state a “commission” — essentially a legalized kickback — that ranges from 15 percent to 60 percent either as a portion of revenue, a fixed upfront fee or a combination of both. According to a new report by the Prison Policy Initiative, a research group based in Massachusetts, depending on the size of the kickback, a 15-minute call can cost the family as little as $2.36 or as much as $17.

Prison officials and phone companies that defend the system of commissions say that extra charges are necessary to pay for the security screening required when inmates make calls. But this presents no problem in New York State, which banned the kickbacks several years ago and required its prison telephone vendor to provide service at the lowest possible cost to the inmates and their families.