The sales agent said he worked for Medicare. He really worked for a private insurer. And, after he came to Dorothy Consalvo's Stockbridge home and signed her to a new insurance plan, one she thought would enhance her existing benefits, the 81-year-old said she was shocked to find she had inadvertently given up her longtime Medicare coverage.

Up the road in Norcross, another agent talked Violet and Carroll Cox into signing up for a private Medicare plan at the low cost of $7 a month. They say they were told it would give them the same coverage as their supplemental insurance. It didn't. "This agent lied all the way," Violet Cox contends.

Esta Lipsky enrolled in a private Medicare plan through an agent the family had used for years. The agent said Lipsky, 90, would not need her supplemental policy and that a Medicare "Advantage" plan would cover those expenses. But the resulting switch cost the Atlanta woman an extra $1,000 when she had treatments for an eye disease.

The metro Atlanta seniors or their families complained to a Medicare fraud and education unit at the Atlanta Regional Commission and have returned to their original Medicare insurance plans. But the same sales traps involving private Medicare plans — run by health insurers as alternatives to traditional Medicare — have snagged other consumers.

State regulators and insurance counselors, here and nationally, have reported widespread complaints about fraudulent tactics used by agents selling private Medicare Advantage plans to seniors.

"These plans are new, and sometimes people are intentionally misled, and sometimes they're just confused by the complexity of the plans," said Victoria Shanahan, a Medicare fraud expert with the Atlanta Regional Commission.

The original Medicare — started as part of President Lyndon Johnson's Great Society in 1965 — is available to people 65 and older and the disabled. Those covered by the federal health insurance can go to any doctor or hospital that accepts the plan. But it doesn't pay all costs, so many seniors also carry "gap" or supplemental coverage.

Private Medicare plans — like the Medicare Advantage policies — have existed for more than 20 years as an alternative to regular Medicare. Medicare Advantage can offer more benefits than basic Medicare and can lower out-of-pocket costs for beneficiaries. But some seniors don't realize the Advantage plans also can limit their choice of physicians and hospitals. Advantage plans — depending on an individual's circumstances — may not save as much money as a supplemental policy, experts say.

Thanks to heavy marketing and funding increases, membership in Medicare Advantage plans recently has jumped to about 9 million people — about 20 percent of the Medicare total. Of the 1.1 million Georgians on Medicare, 94,000 now have a private Advantage plan. The Centers for Medicare and Medicaid Services said the Advantage plans have high satisfaction rates.

Nevertheless, in Georgia, Insurance Commissioner John Oxendine formed a task force last year to address what he called a "shocking number" of complaints about the Advantage plans. High commissions for agents — in the range of $300 to $600 per enrollee — help drive fraudulent sign-ups, Oxendine said.

"They're pretty hefty commissions," he said. Fraud allegations, he said, include agents forging people's signatures. Two deceased individuals were allegedly signed up for Medicare Advantage as well, Oxendine added.

Agents aren't involved in enrollments in traditional Medicare, so they can make no commission from those plans.

Data from Oxendine's office show 40 of the 66 Medicare Advantage complaints it has deemed justified since 2006 have involved marketing and sales. Of those, a third were referred to the department's fraud division. Most involved actions by the agent.

One Georgia agent, for example, faces felony charges in the sale of Medicare Advantage plans to disabled and brain-injured people without their knowledge or consent.

GeorgiaCares, a state insurance counseling service for Medicare and prescription drug coverage, probably receives the most Advantage complaints. "Our call volume is about 1,400 per month, and at least 50 percent are Medicare Advantage-related calls," including complaints and requests for information, said Lisa Federico of GeorgiaCares.

It can take weeks to extract a senior from an Advantage plan and back into original Medicare, Federico said.

The marketing of the plans has ramped up recently because open enrollment for Medicare benefits ends March 31.

Many seniors prefer Advantage policies because they offer some benefits, such as wellness, dental and vision plans, that original Medicare doesn't cover.

Still, the Medicare agency recognizes the sales abuses. It has audited, fined and monitored health insurers over the past year, and is developing new sales regulations for companies.

Congress also has proposed tougher regulations. Even the insurance industry has called for better disclosure of information and a ban on cold calling and door-to-door marketing.

"Industry groups don't usually campaign for additional regulation," said Karen Ignani, president of America's Health Insurance Plans, a trade group. "Our members feel it's warranted in this case."

Medicare — annually a target for budget cutters — also has taken political heat over extra payments made to Advantage insurers. The private plans receive 12 percent more per enrollee than it costs the government to cover a senior in original Medicare — money that has fueled revenue growth for insurance companies. Administration officials cite Advantage plans' extra benefits and coordination of care in defending the additional funding.

Democratic leaders and advocacy groups such as AARP have called for the elimination of the extra payments to Advantage plans.

Meanwhile, a recent Government Accountability Office study said seniors in Medicare Advantage plans may have higher out-of-pocket costs for certain services than people in original Medicare. The Medicare agency disputes the study's findings.

Good candidates for Advantage plans, said GeorgiaCare's Federico, can include:

• A relatively healthy person who doesn't use many medical services and doesn't mind switching doctors.

• A young disabled person who uses medical services often and doesn't have a Medicare supplement policy.

• And an individual with a chronic disease who may benefit from a "special needs" plan, as long as they're sure their doctors will accept their payment.

Two Georgians who rate their Humana plan highly are Genevieve and James Williams of Snellville.

Their extra benefits include a free gym membership. Humana's SilverSneakers fitness program has improved their physical condition, said Genevieve, 70.

Through the workouts, she has lowered her total cholesterol from 275 to 178. "I've cut my cholesterol medicine in half," she said.

Staff writer John Perry contributed to this article.