When incarcerated people face abuse and mistreatment, they can typically file a formal complaint with jail or prison administrators. In federal prisons, the system for resolving these complaints is known as the "Administrative Remedy Program," but it's more commonly referred to as a "grievance system" in state prisons and local jails. Grievance systems are supposed to provide incarcerated people with a way to challenge issues they face behind bars " such as inadequate medical care, harassment by corrections officers, or unsanitary living conditions " and (hopefully) receive some kind of relief. In practice, however, incarcerated people who turn to grievance systems are forced to run a gauntlet of rules and regulations just to be heard, and very rarely succeed. This is especially true when it comes to medical complaints: our analysis of a decade of data from the Data Liberation Project finds that, between 2014 and 2024, a startling 98% of medical grievances were rejected for reasons ranging from the bureaucratic (such as using the wrong size sheet of paper) to the substantive (actually being denied on the merits of the complaint). Less than 1% of medical cases ended in a grant of relief. Conditions are so bad on the inside that since 2000, roughly half of all state prison systems have been court-ordered to improve mental and medical healthcare. In practice ... the grievance system is a black hole, a time-waster, and a deterrent to complaining at all.