There's currently more than €2.7m of unpaid emergency department bills at UHG.
The figure was revealed at a recent meeting of the HSE Health Forum West following a question from Councillor Shane Forde.
The majority of the debt - over €1.7m - is outstanding for more than a year, while a further €1m is outstanding for less than 12 months.
There's also €685 thousand in outstanding in ED charges at Portiuncula Hospital in Ballinasloe.
HSE Health Forum member, Councillor Shane Forde, thinks most of the money will never be collected.