employer-based是針對資金來源，就是僱員的保險，投保資金來源是僱主，而其中，60%是僱主掏錢直接給自己的僱員買保險。見鏈接參考：
The 273 million non-institutionalized persons under age 65 either obtained their coverage from employer-based (159 million) or non-employer based (84 million) sources, or were uninsured.
There were 159 million with employer-based coverage, 84 million with other coverage, and 30 million uninsured.[1]
Of the 159 million with employer-based coverage, many are in self-funded health plans - about 60% in 2017[12]

如果您已經擁有僱主提供的負擔得起的健康保險，您不需要 做任何事。但您仍可進行申請，以查看您或您的家庭成員是 否有資格透過 Covered California 獲得更實惠的健康保險。

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Note added at 2小时 (2020-10-03 13:32:15 GMT)
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https://www.zhihu.com/question/59799941
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