The digital, direct-to-consumer health insurance company known as Oscar filed to go public this week. The insurer has signed up about half a million people in 18 states and is valued at an estimated $8 billion. 

But the picture for health insurance innovators is not all rosy. Last month, Haven, a health care venture founded by Amazon, Berkshire Hathaway and JPMorgan, shut down.

Even online insurance marketplaces like the Zebra find it challenging to list health insurance companies. Chief Technology Officer Meetesh Karia said Zebra focused on the auto and home insurance sectors instead.

“The investment we would need, from time, money, to do [health care insurance] right, that would be significant, and that was a definite risk. So it was one of those where we didn’t want to place our energy and focus there,” Karia said.

Health care is complicated. There are lots of moving parts, including state and federal regulations, privacy concerns, hospital networks and pharmaceutical pricing. 

Then there’s all the uncertainty around the Affordable Care Act and its marketplaces over the past nine years, said Nikhil Krishnan, founder of the comedic newsletter about health care called Out-of-Pocket. 

He said, “It’s really hard to start a new business in health care from both a compliance-regulatory standpoint as well as just upfront costs.”

And, said health services researcher Dr. Aaron Carroll, it’s hard to recoup those costs because of the business model. “Health insurance is just about moving money from here to there.”

But the way people access and use health care is different now, according to Katherine Baicker, a health economist at the University of Chicago. “People are much more comfortable with e-everything,” she said.

So people may be more willing to buy direct-to-consumer health insurance, and disruptors may see new ways to make money, Baicker said. “There’s this potential to harness Big Data to change the way we design insurance products.” 

And that could mean more health insurance innovation coming soon.