Out-Of-Network Utilization and Plan Selection Among Medicare Advantage Cost Plan Enrollees.

Area of Science:

• Health Services Research
• Health Economics
• Medicare Policy

Background:

• Medicare Advantage (MA) plans offer alternatives to traditional Medicare (TM).
• MA 1876 Cost plans allowed out-of-network care coverage through TM.
• The discontinuation of many MA 1876 Cost plans in 2019 provides a natural experiment to study network impacts.

Purpose of the Study:

• To examine how Medicare Advantage network structures influence healthcare utilization and enrollment decisions.
• To analyze the effect of MA 1876 Cost plan discontinuation on member choices.

Main Methods:

• Utilized 2019 MA plan data to identify discontinued Cost plans.
• Employed administrative Medicare enrollment and TM claims data (2018-2019).
• Assessed out-of-network utilization patterns in 2018 and enrollment shifts in 2019 using regression analysis.

Main Results:

• In 2018, 69% of Cost plan enrollees used non-emergency out-of-network care across various specialties.
• Discontinued Cost plan enrollees showed adverse selection in 2019.
• A higher risk score correlated with a 26.35% increased likelihood of enrolling in traditional Medicare.

Conclusions:

• High out-of-network utilization highlights the value MA enrollees place on broad network access.
• Enrollment patterns post-discontinuation suggest higher-risk individuals prefer broader networks, opting for TM.
• Limited MA networks may drive significant selection behavior towards traditional Medicare.