What is MANDATORY SUPPLEMENTAL BENEFITS?
MANDATORY SUPPLEMENTAL BENEFITS meaning Services not covered by Medicare that enrollees must purchase as a condition of enrollment in a plan. Usually, those services are paid for by premiums and/or cost sharing. Mandatory supplemental benefits can be different for each Medicare Advantage plan. Medicare Advantage Plans must ensure that any particular group of Medicare beneficiaries does not use mandatory supplemental benefits to discourage enrollment.
reference: Centers for Medicare & Medicaid Services