The U.S. Department of Health and Human Services has received complaints from around the country about unsolicited tests being billed to Medicare. Could this be a trial run for further fraud?

The proposed changes would be particularly important for patients undergoing treatments that weaken the immune system, giving any dental infections the opportunity to spread.

As early as three weeks after Medicare's drug plan enrollment period ends, insurance plans can change what they charge for drugs.

The number of beneficiaries in employer-sponsored Medicare Advantage plans has gone from 1.6 million in 2008 to more than 5 million.

Under the new rules, private Medicare insurance plans could require patients to try cheaper drugs before moving on to more expensive options.

The Centers for Medicare & Medicaid Services (CMS) has expanded how it defines the "primarily health-related" benefits that insurers are allowed to include in their Medicare Advantage policies.