Seven health insurers have signed up to offer benefits plans in the online insurance exchange that will begin enrolling Georgians in October.

And the companies are offering rates that are comparable to or even below current employer premiums, according to Bill Custer, a health insurance expert at Georgia State University, who was asked to evaluate the filings for GHN.

Aetna, Alliant, Blue Cross and Blue Shield of Georgia, Coventry, Humana, Kaiser Foundation Health Plan, and Peach State will offer a range of plans for individuals in Georgia as part of the Affordable Care Act’s exchange, or “marketplace,” which will debut in 2014.

Missing from the list of insurers is the heavyweight UnitedHealthcare, as well as Cigna. United holds a large share of members in the State Health Benefit Plan.

“On average, these plans are coming in slightly less than premiums of employer plans,’’ said Custer.

He said he based that assessment on premiums for a single person in employer plans in the 2012 Kaiser Family Foundation/HRET benefits survey, where an HMO plan for an individual in the South averaged $456 per month.

“A lot of the fears about premium shock are unfounded, at least in these preliminary filings,’’ Custer said.

Media  reports of competitive rates also have followed insurer filings for exchanges in Oregon, Washington state and California.

The online marketplaces are one of the key ways the health law expands coverage to millions of people not offered coverage by their employers.

The other way is expansion of states’ Medicaid programs, which is up to individual state governments. Gov. Nathan Deal and others in Georgia’s Republican leadership say they won’t agree to expansion here.

The federal government will run the health insurance exchange, or marketplace, in Georgia and many other states. The goal is for individual consumers to be able to make informed choices comparing benefits and price.

The plans in the marketplace are rated Platinum, Gold, Silver and Bronze, based on their level of benefits. The Georgia filings’ Silver plans compare very well with the value of employer plans, Custer said.

Rates for individuals differ based on their age, tobacco use, and region of the state; covering dependents adds to the cost of premiums. Four insurers are offering plans in most, if not all, regions of Georgia: Blue Cross, Humana, Alliant, and Coventry.

Plans in the Atlanta area will have lower premiums than those offered in other parts of the state, according to the filings, obtained by GHN through the state Open Records Act.

“Atlanta is the more competitive market,’’ Custer said.

Among the regions with the highest premiums will be the Albany area, where a recent merger of hospitals is being fought by the Federal Trade Commission. The FTC calls the Phoebe Putney merger with Palmyra anti-competitive.

State Insurance Commissioner Ralph Hudgens, an opponent of the Affordable Care Act, told GHN in a statement that he is concerned that the 2010 law “will drastically increase the price Georgians pay for health insurance.’’

Hudgens added, “I am having those rates reviewed by independent actuaries and will carefully scrutinize each rate to make sure that consumers are protected against unnecessary and excessive increases. Insurers cannot expect to hide behind changes in federal law as a pretext for boosting their bottom line. ”

Custer said that young adults, as expected, will generally pay higher premiums than they do now.

He added that his son, 29, who has a pre-existing condition, recently obtained an insurance policy with a high deductible. He said his son’s premium for a similar plan in the exchange would be 10 percent higher, but that he would also be eligible for the new government subsidies, which would lower that rate.

More than 800,000 Georgians will be eligible for the subsidies next year to buy coverage in the health insurance exchange, according to a report from Families USA.

The report also found that most Georgians eligible for credits are in working families and have incomes between two and four times the federal poverty level, or about $47,100 to $94,200 for a family of four.

Graham Thompson of the Georgia Association of Health Plans agreed that the insurer rates filed for the marketplace are competitive.

The market for the Georgia exchange could potentially be in the hundreds of thousands, Thompson said. Insurers, he said, “are getting out and being aggressive [to gain] market share.’’

Rural areas have some higher rates because costs are harder to manage there, said Thompson, citing rural southwest Georgia in particular. “Where there’s robust competition and choice, insurers are offering competitive prices.”

UnitedHealthcare, in a statement Friday to GHN, said it continues to evaluate exchanges and sees 2014 “as just the very start of the exchange markets.”

“As the economics, sustainability and dynamics of the exchange continue to become clearer over time, the exchange has the potential to be a growth market with much to offer UnitedHealthcare, other insurers and consumers,’’ said Tracey Lempner, a spokeswoman.

The surprise marketplace entrant is Peach State, which covers just Medicaid and PeachCare currently in Georgia.