On August 13, 2009, CMS announced that the average monthly premium for standard Part D prescription drug coverage will be $30 in 2010, up $2 from the 2009 average premium. For 2010, CMS will be conducting a “Medicare Demonstration to Revise the Part D Low-Income Benchmark Calculation,” which will have the effect of decreasing the number of low-income beneficiary reassignments to plans with premiums below the 2010 subsidy amount. Nevertheless, CMS estimates that approximately 800,000 Medicare beneficiaries who are eligible for low-income subsidies will need to change plans in 2010 to remain in a zero-premium plan. CMS also released the 2010 national average monthly bid; the base beneficiary premium; the regional low-income subsidy premium amounts for 2010; and the 2010 Medicare Advantage regional preferred provider organization benchmarks. In addition, CMS has revised its Medicare Marketing Guidelines to reflect Medicare Improvements for Patients and Providers Act changes, effective August 7, 2009.