These are the areas of California that could be most affected by repeal of Obamacare

Protesters gather at the Trump International Hotel & Tower in New York on Jan. 15 to demonstrate against Republican plans to repeal Obamacare.
Protesters gather at the Trump International Hotel & Tower in New York on Jan. 15 to demonstrate against Republican plans to repeal Obamacare. The New York Times

A repeal of the Affordable Care Act without some form of replacement insurance would have profound effects in California, particularly in counties with a high proportion of impoverished residents.

President Donald Trump and Congress have taken steps to repeal the ACA, often called Obamacare. Lawmakers supporting repeal, mostly Republicans, have promised to replace Obamacare with another form of broad-based coverage but have not yet rallied around an alternative.

The ACA mandated that individuals obtain health insurance coverage or pay a tax penalty. It increased access to insurance largely through two vehicles: an insurance exchange, known here as Covered California; and the expansion of Medicaid, government insurance for the poor, which is called Medi-Cal in California.

Most Californians who obtained insurance following the 2009 passage of Obamacare did so through the Medi-Cal expansion. About 3.7 million California adults, or one-eighth of the state’s adult residents, obtained insurance through Medi-Cal following the expansion, according to the UC Berkeley Center for Labor Research and Education and the UCLA Center for Health Policy Research.

Republicans in Washington are discussing how to handle the Medicaid expansion. The large majority of funding for expansion – tens of billions of dollars – comes from the federal government. Some Republican governors have argued against reversing Medicaid expansion because it provides coverage for so many people in their states.

Repealing Obamacare also could affect the roughly 1.2 million Californians who receive subsidized health insurance through Covered California. Some of those residents might welcome the change: They only buy (often expensive) insurance to avoid paying a fine. Others see the ACA as vital to their ability to obtain coverage.

A substantial proportion of residents in every California county obtained new health insurance coverage following the implementation of Obamacare. In Los Angeles County alone, more than 1.5 million residents obtained coverage through the expansion of Medicaid or Covered California, UCLA figures show. More than 250,000 residents of the four-county Sacramento region obtained coverage through Medicaid expansion or Covered California.

It is unclear what would happen to these residents if Obamacare is repealed. Trump has promised to replace Obamacare with a program that will “broaden health care access, make health care more affordable and improve the quality of the care available to all Americans.”

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Phillip Reese: 916-321-1137, @PhillipHReese

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