What are the basic guidelines for the Humana Part D drug plan?

As of 2015, each Humana Part D drug plan has its own guidelines but all require participants pay their Medicare Part B premiums, according to Humana. The three Medicare prescription drug plans available are the Humana Walmart Rx plan, the Humana Preferred Rx plan and the Humana Enhanced plan.

Monthly premiums are under $16 on the Walmart Rx plan, notes Humana. Additionally, Tier one and Tier two drugs require no deductible, and a 90-day mail order supply may require no co-pay. The co-pay for generic prescription drugs purchased in Walmart, Walmart Express, Sam's Club and Neighborhood Market pharmacies may cost as little as $1.

Humana Preferred Rx plan subscribers pay an annual $320 deductible as well as a monthly premium, advises Humana. Tier one prescription drugs purchased in-store at Walmart, Walmart Express, Sam's Club and Neighborhood Market pharmacies may cost as little as $1 after the deductible. Tier one and Tier two drugs require no deductible, and a 90-day mail order supply may require no co-pay after the deductible.

The Humana Enhanced plan requires no deductible and offers fixed co-payments, explains Humana. Subscribers in the coverage gap may also qualify for select prescription brand coverage on the Humana Enhanced plan.