Beneficiaries who are in the “doughnut hole” stage of the Medicare prescription drug benefit are paying too much for their drugs, a new study by Consumers Union indicates.

The report, which focused on one Florida county, finds that the lowest retail prices of six common medications are lower at least 80% of the time compared with the prices beneficiaries pay for these drugs when they are in the “doughnut hole.” Within that span, Medicare beneficiaries are responsible for 100% of annual prescription drug costs between $2,250 and $5,100. Medicare covers 95% of annual prescription drug costs that exceed $5,100.

For the study, researchers studied retail prices for Lipitor, Toprol, Synthroid, Norvasc, Zoloft and Hydrocodone at 261 pharmacies in Broward County. Retail prices in some cases were 10% lower than those Medicare beneficiaries would pay in the doughnut hole.