Negotiating for Seniors Act - Amends part D (Voluntary Prescription Drug Benefit Program) of title XVIII (Medicare) of the Social Security Act to repeal the prohibition against: (1) interference by the Secretary of Health and Human Services (HHS) with the negotiations between drug manufacturers and pharmacies and prescription drug plan sponsors, and (2) the Secretary's requiring a particular formulary or instituting a price structure for the reimbursement of covered Medicare part D drugs.