4. How does the deductible for Part D work? Posted on September 11, 2017 at 12:52 pm.Written by advantage_admin This is the amount you must pay every year for your prescription drugs before your Medicare Prescription Drug Benefit begins paying for covered medications. Deductibles vary according to the Medicare prescription drug plan. No Medicare prescription drug plan may have a deductible over $400 in 2017. Certain Medicare prescription drug plans don’t have a deductible. Post navigation 8. Can I add more people to my Medicare Advantage plan?9. What’s the difference between Medicare plans?