WASHINGTON — Seeking momentum on the eve of a crucial meeting on health care reform, congressional Democrats on Wednesday seized on evidence that California’s largest for-profit health insurer spent tens of millions of dollars on lavish corporate retreats and executive salaries even as it planned dramatic rate hikes for nearly 800,000 customers who buy coverage on their own.

Executives at WellPoint, the parent company of Anthem Blue Cross of California, came under fire at a House hearing after internal e-mails and other documents suggested that the company systematically works to curb how much it spends on medical claims, while prodding sicker patients into stingier plans with greater cost-sharing. The showdown was sparked by Anthem’s plan to raise rates for its roughly 800,000 customers in California’s individual market by as much as 39 percent, starting in May.

One day before a bipartisan health care summit that could prove critical to the fate of President Barack Obama’s health reform plans, Democrats on a House panel took a populist tack, contrasting what they portrayed as the extravagant lifestyles of insurance executives with customers facing ever-rising costs.

“Corporate executives at WellPoint are thriving,” said House Energy and Commerce Committee Chairman Henry Waxman, D-Los Angeles, “but its policyholders are paying the price.”

WellPoint executives responded that the firm is subject to the whim of larger forces in the health care market, such as higher charges by hospitals and drug companies. The slumping economy has prompted many healthy customers to drop their coverage, they said, leaving the company with little choice but to raise rates for those who remain on the rolls.

“There is so much misinformation about what is driving these premium increases,” WellPoint President and CEO Angela Braly told the House Energy and Commerce Subcommittee on Oversight and Investigations.

But the e-mails and documents obtained by the committee gave Democrats ammunition to question the company’s motives. One e-mail written by a WellPoint vice president in October stated that a premium increase averaging 23 percent would “return CA to target profit of 7 percent.” Others referred to creating slimmed-down policies (called “downgrade options”) as a way to retain customers turned off by premium hikes.

WellPoint said it wound up targeting a profit margin of 2 percent, which it described as reasonable. Scaled-back policies, the insurer said, represent an effort to keep coverage affordable.

WellPoint was also put on the defensive by documents showing it paid 39 executives more than $1 million in 2008 and spent more than $27 million on 103 executive retreats in 2007 and 2008. Among the destinations were a Four Seasons Resort in San Diego and a resort in Manele Bay, Hawaii. Braly said the functions were “meetings for our customers,” including brokers and agents, and that the company is doing what it can to keep costs in check for subscribers.

“We’re fighting every day to make sure we can make their health plans more affordable,” she said.

Despite the firestorm of criticism, Anthem representatives said this week they plan to move ahead with the rate increase — averaging 25 percent but as much as 39 percent for some customers — for about 800,000 Californians enrolled in individual plans, as opposed to group plans provided by employers. State Insurance Commissioner and gubernatorial candidate Steve Poizner is reviewing the proposed rate hike but is mostly powerless to stop it.

The firm’s rate hike proposal has become a political football in the health care debate. Obama this week used it to justify his new plan to give the federal government power to block health care premium increases that are deemed “excessive” — an idea floated a few days earlier by Sen. Dianne Feinstein, D-Calif.

Democrats said steep rate hikes in California and other states demonstrate the need for sweeping health care reform. Obama says his plans would keep premiums in check by bringing most Americans into the market — healthy and ill — with a mandate to buy insurance. That would spread costs more widely, he argues.

But the insurance industry remains opposed, saying the requirement to buy coverage isn’t strict enough. The industry fears that it will be forced to accept people with pre-existing conditions without any assurance that those costs will be balanced out by healthy subscribers.

Contact Mike Zapler at 202-662-8921.