Reducing prison phone rates was a focus for Clyburn when she was a commissioner and has been a priority for her since she took the helm of the agency in May.
Prisons request bids from telephone companies to provide service and require each bid to include a fee to the prison. Critics argue the system encourages exorbitant rates.
A typical interstate collect call from prison has a $3.95 connection fee and rates as high as 90 cents per minute, according to civil liberties groups. A 15-minute collect call could cost families $10 to $17, and a one-hour call once a week would cost $250 per month.