Carolyn McClanahan, a Jacksonville, Florida-based financial advisor and medical doctor, told CNBC that she's steered at least five such clients, whose individual net worths range between $1 million and $3 million, toward buying Obamacare health plans because of the federal subsidies available due to their taxable income levels.

Those clients are saving between $4,600 and $8,800 in annual premium payments as a result of subsidies. On top of that, McClanahan said, those customers are getting extra financial help to pay their out-of-pocket health expenses — the copayments, coinsurance and deductibles that aren't covered by their insurance plan.

The idea of giving rich people discounted Obamacare plans raises the eyebrows of even McClanahan's clients, who were initially skeptical when she described the option.

"Everybody was like, 'Are you sure this is going to work?'" McClanahan said of her clients' reaction.

"And I'm like, 'Yes, I'm sure it's going to work.'"

And it's legal as well, because of the way the Affordable Care Act focuses on income rather than net worth to establish eligibility for Obamacare aid.

"The law was set up that way, so I'm going to help them take advantage of it."

The ACA was enacted primarily to help uninsured people get health coverage at a price they could afford. To help do that, the ACA authorized the federal government to issue tax credits, or subsidies, to people with low or moderate incomes who buy health plans sold on government-run Obamacare exchanges.

For 2016, individuals with annual taxable income between $11,770 and $47,070 qualify for such aid.