The Justice Department accused large insurers of colluding with national brokers to steer older people and those with disabilities toward coverage that might not offer the best medical care.

The Justice Department on Thursday accused three of the nation’s largest health insurers of paying hundreds of millions of dollars in illegal kickbacks over several years to insurance brokers that steered people into private Medicare plans.

Federal prosecutors also accused two of the insurers of colluding with brokers to discriminate against people with disabilities, by discouraging enrollment in the private Medicare plans because the insurers believed coverage would be more costly.

About 12 percent of Medicare beneficiaries are younger than 65, covered by the federal insurance program because they are disabled. Their care can be expensive given complex health needs.

According to the complaint, originally brought by a whistle-blower and joined by the Justice Department, three of the nation’s largest health insurance companies — Aetna; Elevance Health, formerly known as Anthem; and Humana — are accused of paying kickbacks to three large brokers, eHealth, GoHealth and SelectQuote, to increase enrollment in their Medicare Advantage plans. Those brokerage firms are also charged with misconduct.

The complaint, filed in a federal court in Boston, asserted that the kickbacks occurred from at least 2016 through 2021, and it accused Aetna and Humana of discriminating against people with disabilities.

Aetna, Elevance, GoHealth and Humana denied the allegations, while the others did not immediately respond to requests for comment.