The Centers for Medicare & Medicaid Services Friday released premium and cost information for Medicare Advantage and Part D prescription drug plans for the 2018 calendar year. The average Medicare Advantage premium will decrease by $1.91 to $30, while the average monthly premium for a basic Medicare Part D prescription drug plan will decrease by $1.20 to $33.50, the agency estimates. The average number of MA plan choices per county will increase to about 29, CMS said. It projects MA enrollment will climb by 9% to 20.4 million, or 34% of Medicare beneficiaries. Open enrollment for 2018 Medicare health and drug plans begins Oct. 15.