According to a report by Kaiser Health News, the majority of US hospitals are being penalized by Medicare for having patients frequently return within a month of discharge. The price tag associated with the penalties is a combined $420 million, government records show.

The report outlines the impact of the Hospital Readmissions Reduction Program, created by the Affordable Care Act. In the fourth year of federal readmission penalties, 2,592 hospitals will receive lower payments for every Medicare patient that stays in the hospital — readmitted or not — starting in October 2015. All but 209 of the hospitals penalized this year were also punished last year, Kaiser Health News reported.

Since the fines began in October 2012, national readmission rates have dropped, but roughly one of every five Medicare patients sent to the hospital ends up returning within a month.

The fines are based on readmissions between July 2011 and June 2014 and include Medicare patients who were originally hospitalized for one of five conditions: heart attack, heart failure, pneumonia, chronic lung problems (COPD) or elective hip or knee replacements.