Let the blame game begin over ObamaCare’s oversights.

The nation’s largest health insurer, UnitedHealthcare, claims the Affordable Care Act is responsible for forcing it to boot doctors from its Medicare Advantage program that serves thousands of elderly patients in the New York metro region.

CEO Jack Larsen, under fire for separating seniors from their MDs, took out full-page ads to explain that cuts in Medicare spending forced the ­insurer’s hand.

“We are working to collaborate with a more focused network of physicians to help us provide higher quality and more affordable health care coverage to meet the needs of our members, and help them get more from their health plan benefits,” Larsen said.

“This work has become even more urgent in light of the severe funding reductions for Medicare Advantage plans that have come from Washington.”

Even fervent supporters of ObamaCare are investigating complaints that elderly patients are being unnecessarily separated from their doctors.

“We’ve met with New York doctors and we’re looking for the best way to ensure seniors maintain access to the doctors they want,” said Max Young, a spokesman for Sen. Chuck Schumer (D-NY).

“We’re looking at why United has kicked doctors off their plan, and if their explanations are truthful.”

The politicians will soon be hearing from enraged seniors.

The state medical society has drafted a form letter that is being handed out to patients in doctors’ offices throughout the city.

“The timing of this action seems curious. Insurance companies are taking full advantage of the chaos surrounding the rollout of the Affordable Healthcare Act. Did they think seniors would not be paying attention to this issue while the spotlight was focused on the glitches related to the national health care program?” reads the protest letter to Congress .

Meanwhile state insurance officials are warning that medical premiums could skyrocket in year two of ObamaCare, if not enough of the so-called “young invincibles” sign up for coverage in year one, which is 2014.

“If you don’t have that young healthy population enrolling, it’s going to have an impact on premiums,” said Leslie Moran of the New York Health Plan Association, the trade group for commercial insurers.

State, federal and insurance officials have yet to release the age and demographic data of those who have signed up, leading critics to suspect the worst.

“We are not providing any enrollment information at this time,” said Maria Gordon-Shydlo, aa UnitedHealthcare spokesman said.

The state Health Department said an age breakdown will be released shortly.