HHS Implements Inflationary Rebates For List Prices Of Almost All Medicare Part D (Outpatient) And Some Part B (Physician-Administered) Drugs The inflationary cap on list price growth will impact drug makers, which have already seen their net prices stagnate in recent years and even enter negative territory. It will also lower Medicare beneficiaries' out-of-pocket spend and affect price negotiations between PBMs and drug makers.