The new year has already seen 106 accountable care organizations (ACOs) participate in the Medicare shared savings program, as federal health officials try to demonstrate that new health reform programs, powered in part by better IT, are starting to pay off.

“ACOs have helped to set Medicare on a more sustainable path today and into the future, as well as serve as a model for what improvements are possible for our nation’s health care system,” Jonathan Blum, Centers for Medicare and Medicaid Services’ (CMS) acting principal deputy administrator, wrote in a recent blog post.

About 4 million American seniors, or eight percent of the country’s 49 million Medicare members, are now receiving care through an ACO, with more than 250 of the payer-provider partnerships forming since the Affordable Care Act (ACA) became law.

[See also: Seven states sign on to accountable care initiative.]

Among the crop of ACOs launching this year, 15 are following the advanced payment model, which helps bring physician-based and rural providers a form of capital investment for infrastructure needed for care coordination, like electronic health record systems and information exchange capabilities.

As insurers like Cigna and the Blues partner with physician and provider practices, Florida will be one of several states where the ACO model will be put to the test. Florida is now home to 8 advanced payment ACOs, along with dozens of Medicare shared savings ACOs.

CMS is betting on the success of ACOs as well, with the ACOs subject to 33 quality measures on care coordination, patient safety and preventive services that federal officials say could translate into almost $1 billion in Medicare spending savings over four years.

One of an ACO’s main tools is health information exchange, which is especially important considering the focus on patient provider options.

“Accountable care is all about allowing the patient to see who they prefer for care,” said Dev Culver, executive director of Maine HealthInfoNet, as the statewide HIE launched a project with the state’s all payer claims database. “That creates a problem for the organization that has the contract. It’s very hard for them to see the clinical activity going on across town.”

As CMS prepares to manage the shared savings program over the next few years, officials are pointing to signs that ACOs and other health reform efforts, being implemented bit by bit, are starting to work as intended.

[See also: ACOs deliver care to 31 million Americans, report finds .]

Actuaries from HHS’s Assistant Secretary of Planning and Evaluation estimated recently that the growth in Medicare expenditures has slowed to 0.4 percent per beneficiary in 2012, compared to the 3.4 percent growth in the U.S. per capita GDP and Medicare’s 2.7 percent growth rate between 1970 to 2010.

Researchers from CMS and the Congressional Budget Office estimate that the ACA in total should reduce the rate of Medicare growth per beneficiary by approximately 1 percentage point a year in the next decade, as 20 to 30 million baby boomers get set to join the program.