How to pick a Medicare Part D plan during open enrollment

Part D is the prescription drug plan that sits on top of Original Medicare. Open enrollment is the window to switch plans without a penalty. The cheapest premium is rarely the cheapest year if your drugs sit on a high tier or need prior authorization.

Enter every drug and dosage into the official plan finder, including the pharmacy you actually use. Mail-order pricing can differ from the corner store. A plan that looks cheap at a preferred pharmacy can cost more if that pharmacy is a 40-minute drive.

Watch the deductible, the coverage gap, and the out-of-pocket cap. A $0-deductible plan with high copays can still cost more than a plan with a deductible and lower tiers for your specific list.

If you take insulin, specialty drugs, or a new prescription added mid-year, re-check the formulary before you lock the plan. Formularies change every January. A drug that was Tier 2 last year can move to Tier 4 without a letter you will notice.