 The theory is that the risk-based formula will not affect spending, but in practice it almost always increases cost per beneficiary by one or two percent, either because the Medicare Advantage plan is diligent in upcoding to a beneficiary's specific risks or because patients on FFS Medicare, where providers have no incentive to code at all, are undercoded.Based on the 2019 benchmark/bidding/rebate process, the Medicare Advantage average monthly plan premium in 2020 is estimated to decrease 14 percent to $23.00 from an average of $26.87 in 2019.Since 2017, the average monthly Medicare Advantage premium has decreased by an estimated 27.9 percent.