How Much Does Medicare Cover For Prescriptions? 
`` Original '' Medicare will cover SOME medications under Part B . As a general rule , infusion therapy , immunizations administered in your doctor 's office and most diabetic supplies -LRB- including insulin -RRB- may be covered under Part B. Most prescriptions filled on an outpatient basis by mail order or at a retail pharmacy are covered under Medicare Part D. Your Part D prescription drug plan is a separate benefit offered by private insurance carriers . The premium you pay will vary by zip code and the covered medications . Many Part D plans have an annual deductible that must be satisfied before brand name prescriptions are included with copay 's . Be sure to verify that the medications you take are included in your Part D drug formulary You can compare drug formulary 's at Medicare.gov by using the drug formulary prescription plan finder . 