Just make sure that you are comparing apples to apples -
Yahoo News - 10/01/2019 - Humana’s 2020 Medicare Health Plans Announcement
from the link ~
For 2020, Humana will introduce a new co-branded prescription drug plan with Walmart Inc. This new plan, called Humana Walmart Value Rx, will have a national monthly plan premium of $13.20. In 2020, Humana will also offer the Humana Premier Rx and Humana Basic Rx stand-alone prescription drug plans nationally.