Who is Obamacare's biggest winner?

The answer to that question, of course, depends on the context in which it's presented. There are political winners (and losers) from implementation of the Affordable Care Act. Some individuals gained, but others didn't. The same is true for companies.

While hospitals benefited from the anticipation of Obamacare, their stocks didn't perform nearly as well as implementation approached and ultimately started. Gains for insurers participating in Obamacare have been mixed. One company, though, stands out from the crowd as probably the single biggest real winner from Obamacare so far -- private health insurance exchange operator eHealth (NASDAQ:EHTH).

Path to success
Over the last 12 months, shares of eHealth have skyrocketed 130%. The jump looked even more impressive earlier this year, when the stock peaked above $60 per share. Although eHealth's shares now trade at around $45, the company emerged as a huge winner from Obamacare.

It wasn't necessarily an easy path to achieve success. Gary Lauer, eHealth's CEO, camped out in Washington, D.C. quite a bit trying to persuade federal officials to allow eHealth to sign up individuals for insurance under the health reform law. EHealth's lobbying expenditures also more than doubled during the three-year period beginning in 2011 compared to the prior three-year period.

The company's big break finally came last July. EHealth and four other online insurance exchanges secured contracts with the Centers for Medicare and Medicaid Services, or CMS, to enroll individuals signing up for insurance offered on the 36 state marketplaces operated by the federal government. 

This news sent eHealth's stock soaring as much as 30% in one day. That was just the beginning. Shares popped in September with the company's deal with Intuit (NASDAQ:INTU) to integrate eHealth's online health insurance comparison with Intuit's popular TurboTax software. EHealth's stock also steadily climbed during October as the federal Healthcare.gov website suffered through an embarrassing launch. 

Beating the feds at their own game
At the end of October, Gary Lauer actually offered to have eHealth replace Healthcare.gov until all of the website's problems were fixed -- for free. While the federal government didn't take him up on that offer, the juxtaposition was powerful. Not only did EHealth not hit any big technical snags, the company performed much better than the feds in a very important area -- the percentage of young Americans enrolling.

According to the U.S. Department of Health and Human Services, individuals between the ages of 18 and 34 made up 27% of total enrollees during February. That's up slightly from previous months, but it's still much lower than what many expected. 

It's also a lot worse than eHealth's record. The private health insurance exchange operator reported 39% of those signing up for Obamacare plans through its website from October through December were in the coveted 18-34 age range. More recent performance was even better. Between Jan. 1 and March 23, these younger individuals made up 45% of total enrollees.

Why was eHealth so much more successful on this front? One reason could be that the company's website is easier to use than the federal site. Perhaps an even bigger factor is that eHealth already attracted a lot of younger Americans. Company spokesman Brian Mast told CNBC that prior to the launch of Obamacare, over 50% of eHealth's customers were young individuals. 

eHealth might also be outperforming the feds in terms of the numbers of uninsured that have been reached. In a survey of shoppers on the company's website who selected Obamacare plans this year, more than half indicated that they were previously uninsured -- up from 34% in the fourth quarter of 2013.

The federal government hasn't released any official figures on how many previously uninsured individuals have signed up. However, a McKinsey survey conducted in February found that only 27% of customers selecting an Obamacare health plan through all possible sources (not just the official exchanges) were previously uninsured. 

RAND Corporation, a non-profit and non-partisan research organization, recently reported a similar finding. According to a recent RAND survey, around one-third of Obamacare enrollees had no health insurance prior to signing up for their new plans.

Waning ways?
We'll soon find out if eHealth is continuing its winning ways. The company reports first quarter financial results on May 1. There are at least a few reasons to think the momentum will keep going.

TurboTax could potentially turbocharge eHealth's fortunes. Intuit counts more than 25 million users of its tax software. Over the past several months, many of them likely opted to find out about their health insurance options via eHealth thanks to the deal signed between the two companies last year.

eHealth's growth opportunity isn't just limited to Obamacare. A partnership forged with Aetna (NYSE:AET) and HR Policy Association in March could lead to more doors being opened. Aetna and eHealth are working together to power HR Policy Association's retiree medical exchange used by many private employers.

However,eHealth currently trades at a multiple of 492 times trailing earnings. Even factoring in expected growth doesn't help too much: The stock's forward price-to-earnings value stands at 98. The private health insurance exchange operator will have to grow tremendously to continue to justify that sky-high valuation. If it doesn't, regardless of what happens with Obamacare, eHealth's winning ways could easily wane.