 Therefore benchmark/framework/competitive-bidding process changes were made in 2010 (effective for the 2012 plan year) to better align the variable per person costs of Part C and the per person costs of people just on Parts A and/or B.As a result, on average counting all the various types of Part C health plans, as reported annually by the Medicare Trustees, over the period 1997-2018 (most recent year available) the cost per person for a person on Part C has been lower on average than the cost per person for a Medicare beneficiary not on Part C (but some years it has been as much as 6% negative and other years it has been as much as 6% positive).However the numbers cannot be completely aligned in any given year without a major change in Medicare law because the benchmark/framework/competitive-bidding for Part C, which happens county by county, for any given year depends on the A and/or B per-person spending in the comparable counties two years prior.