Internal cost estimates from 17 of the nation's largest insurance companies indicate that health insurance premiums will grow an average of 100 percent under Obamacare, and that some will soar more than 400 percent, crushing the administration's goal of affordability.

New regulations, policies, taxes, fees and mandates are the reason for the unexpected "rate shock," according to the House Energy and Commerce Committee, which released a report Monday based on internal documents provided by the insurance companies. The 17 companies include Aetna, Blue Cross Blue Shield and Kaiser Foundation.

The report found that individuals will face "premium increases of nearly 100 percent on average, with potential highs eclipsing 400 percent. Meanwhile, small businesses can expect average premium increases in the small group market of up to 50 percent, with potential highs over 100 percent."

One company said that new participants in the individual market could see a premium increase of 413 percent when new requirements on age rating and required benefits are taken into account, said the report. "The average yearly cost for a new customer in the individual market grows from $1,896 to $3,708 -- a $1,812 cost increase," it added.

The key reasons for the surge in premiums include providing wider services than people are now paying for and adding less healthy people to the rolls of insured, said the report.

It concluded: "Despite promises that the law will lower costs, [Obamacare] will in fact cause the premiums of many Americans to spike substantially. The broken promises are numerous, and the empirical data reveal that many Americans, from recent college graduates to older adults, will not be able to afford the law's higher costs."