Plan includes Medicare Part D prescription drug benefit: $7/$45/$75/33% co-pay; 90-day mail order $0.00 Tier 1, $112.50 Tier 2 and $187.50 Tier 3. Once drug costs exceed $2,830.00, you pay $7.00 co-pay for generics and 100% for preferred, brand and specialty drugs. After total out-of-pocket costs exceed $4,550.00, you pay the greater of $2.40 for generics, $6.00 for preferred and brand name drugs, or 5% co-insurance. .