Many low-income people with Medicare who qualify for Medicaid & the Part D Low-Income Subsidy (LIS) do not enroll in these programs. In this JGIM letter, we show that low Medicaid take-up (esp. partial Medicaid) drives low enrollment in the LIS. https://rdcu.be/b7zQY 

A little known fact about these programs is that Medicaid recipients automatically get the LIS (but not the other way around). We show that LIS take-up almost perfectly mirrors Medicaid take-up & is lower for people who qualify for partial Medicaid (via Medicare Savings Programs)

What is one way to increase take-up of the LIS? Make it easier to get Medicaid. Options could include auto-enrollment of presumed low-income Medicare benes in partial Medicaid benefits that cover the Part B premium (SLMB & QI). Low cost + effective in facilitating LIS enrollment