Encouraging Innovative Benefit Design to Lower Costs for Seniors Act This bill allows prescription drug plan (PDP) sponsors under the Medicare prescription drug benefit to offer additional plans in a region. Specifically, the Centers for Medicare & Medicaid Services (CMS) must update guidance to allow PDP sponsors to offer up to four plans in a region; the CMS may also set a greater limit, as appropriate. PDP sponsors may offer up to two additional plans beyond this limit if the PDP sponsor ensures that, under at least one of the plans, pharmacy benefit managers do not receive any remuneration unless at least 10% of price reductions received from drug manufacturers are reflected at the point-of-sale or otherwise used to reduce beneficiary cost-sharing.