Improving Seniors' Timely Access to Care Act of 2019 This bill establishes several prohibitions, requirements, and standards relating to prior authorization processes under Medicare Advantage (MA) plans. Specifically, the bill prohibits MA plans from instituting additional prior authorization requirements for surgeries (including related items) that are furnished to a patient during other surgeries for which prior authorization was not required or was already received. Additionally, MA plans must (1) establish an electronic prior authorization program that meets specified standards, including the ability to provide real-time decisions in response to requests for items and services that are routinely approved; (2) annually publish specified prior authorization information, including the percentage of requests approved and the average response time; and (3) meet other standards, as set by the Centers for Medicare & Medicaid Services, relating to the quality and timeliness of prior authorization determinations.