To amend title XXVII of the Public Health Service Act and title XVIII of the Social Security Act to prohibit group health plans, health insurance issuers, prescription drug plan sponsors, and Medicare Advantage organizations from limiting certain information on drug prices.

Know the Cost Act of 2018 This bill prohibits a health insurance plan or pharmacy benefits manager from restricting a pharmacy from informing an enrollee of any difference between the cost of a drug under the plan and the cost of the drug without health insurance coverage. (Such restrictions are commonly referred to as gag clauses.)