(AP Photo)

(CNSNews.com) – Major health insurance companies--Blue Cross, Aetna, United, Humana--have decided not to participate in various states in the Obamacare health-insurance exchanges that will be the only place Americans will be able to buy a health insurance plan using the federal subsidies authorized under the Obamacare law.

Under the Patient Protection and Affordable Care Act (AKA Obamacare), every American must buy a health insurance plan that meets minimum government specifications. If a person does not get health insurance through their employer, and is not on Medicaid, they can buy insurance through their home state's insurance exchange (which, depending on the state, will be run by either the state or federal government).

States will also operate exchanges where small businesses can buy health-insurance plans.

Individuals and families making up to 400 percent of the federal poverty level will qualify for a federal subsidy to help them buy their government-mandated insurance--but only if they buy their insurance on the government-run exchange.

Also under Obamacare, insurance companies are required to take customers with pre-existing health problems and to provide certain services mandated either by the law itself or by regulations issued under the law by the Obama administration--thus driving up the insurance companies' costs.

Aetna, a fortune 100 company with $34.2 billion in revenue, has pulled out of the government-run exchanges in three states, including the state of Connecticut, where it is based.

Founded in Hartford, Conn., in 1850, Aetna withdrew its application to participate in that state on Monday, the Hartford Courant reported. The company said it was withdrawing from there and in Georgia and Maryland because limitations the state governments would impose on their rates would not allow them to make money.

“We have spent considerable time identifying those states in which we can be competitive and add the most value to the market,” Aetna said in a statement. “As a result of our analysis, we have reluctantly concluded that we will withdraw certain Individual Exchange filings for 2014, including filings in Connecticut, Georgia and Maryland.”

“This is not a step taken lightly, and was made as part of a national review of our Exchange strategy,” the company said. “Unfortunately, we believe the modifications to the rates filed by Aetna will not allow us to collect enough premiums to cover the cost of the plans and meet the service expectations of our customers.”

California

Aetna will also not participate in California’s exchange, and a spokesperson told CNSNews.com that the company never intended to do so.

(AP Photo)

“We did not withdraw exchange plans in California, as we never planned participation nor filed [Qualified Health Plans] QHPs to participate in the California exchange,” a spokesperson said.

Anthem Blue Cross has withdrawn its bid to participate in the California's government-run Obamacare exchange marketing insurance to small businesses.

United Health Group, the largest health insurer in the United States, has taken a pass on California's individual health insurance exchange.

Aetna will stop selling health insurance policies to individuals in California all together, leaving nearly 50,000 existing individual policyholders to find new coverage by January. The company will continue to directly sell health insurance to employers in California--outside of the government exchange system.

‘If You Like Your Doctor,’ Hope Your Insurer Is Participating in the Exchange

“No matter how we reform health care, we will keep this promise: If you like your doctor, you will be able to keep your doctor, period,” Obama said on June 15, 2009.

“If you like your health care plan, you will be able to keep your health care plan. Period," he said. "No one will take it away. No matter what.”

That promise, however, has been revised by the Department of Health and Human Services (HHS), which now says, “you may be able to keep your current doctor” in the health insurance marketplace.

“Most health insurance plans offered in the Marketplace have networks of hospitals, doctors, specialists, pharmacies, and other health care providers,” HHS said on its website for the health reform law. “Networks include health care providers that the plan contracts with to take care of the plan’s members.”

“Depending on the type of policy you buy, care may be covered only when you get it from a network provider,” they said.

President Barack Obama signs the Affordable Care Act (Obamacare) into law on Mar. 23, 2010. (AP)

With insurers opting out of state-run health insurance exchanges, individuals are left with fewer options.

Following Aetna's departure, only three companies remain in Connecticut’s “Access Health CT” exchange.

Similarly, only five insurers are participating in the exchange in Georgia, after Aetna and Coventry Health Insurance dropped out last week.

The Savannah Morning News noted that this will “leave residents of some parts of the state with limited choice.”

Two of the three largest health insurers in Wisconsin will also not participate in the state’s Obamacare exchange.

Though they will not participate in at least four state-run exchanges, Aetna said they “appreciate” the opportunity to work with state regulators on complying with the ACA.

“We have appreciated the chance to work with the regulators in each state for the past months on a variety of key issues regarding ACA implementation,” Aetna said in a statement. “We will continue to work with them, and various Exchange leadership teams, as we evaluate exchange participation in future years.”