Almost all states allow jails and prisons to charge incarcerated people medical and "room and board" fees, locking them into cycles of debt and possibly more incarceration, an Axios review of new exclusive data found.

Why it matters: The debt wheel targets the majority of the estimated 1.8 million people in state prisons and local jails, putting up more obstacles to escaping the poverty that likely contributed to arrests in the first place.

The big picture: The fees raise hundreds of millions of dollars from victims' funds, DNA databases and other programs, but also help states expand efforts to incarcerate more people.

Unlike other taxpaying constituents, introducing or raising fees on incarcerated people is rarely met with resistance.

And some state lawmakers are unaware that the fees exist.