Tony Miller has spent his entire career thinking about how to improve health insurance for American consumers.

He realized early on he was going to have to innovate on the outside to convince the industry giants to evolve. He’s sold three health benefits startups to UnitedHealth Group, the latest and largest is Bind Benefits, now known as Surest. That acquisition put Miller out of a job—“Bind within UHG is better without me,” he jokes.

But Miller (featured on the TCB 100 in 2019), who is also managing partner of Minneapolis-based Lemhi Ventures where he invests in other health related innovations, is already rolling up his sleeves to work on the next advance: Harbor Health, an Austin, Texas-based care provider designed with the same consumer focus Miller brought to benefits. In a recent interview on TCB’s By All Means podcast, Miller shares his vision for the health care system as well as lessons in being an effective founder—in the bureaucratic world of insurance, and beyond. Here are five.

1. Expect rejection.

“One of the most important ingredients to an entrepreneur: the intestinal fortitude of a sewer rat. You’re going to face a million no’s. Surround yourself with other believers and stick with it. That’s what makes change come into reality.”

2. Assemble a great team.

“In entrepreneurship, you not only have to be excited about the product, but the team. That’s what’s so awesome about being an entrepreneur—you get to work with other entrepreneurs.”

3. Find corporate support.

“Every entrepreneur needs the intrepreneur—someone in a big corporation who is also trying to change the way something works. If you don’t get those insiders to buy into what you’re doing, you’re not going to get off the ground.”

4. Play by the rules when pitching to large organizations.

“Corporations tend to overplay what they think it will take to win. [As scrappy startup founders competing against larger companies for big clients], we followed directions.”

5. Your startup is a totally different entity after an acquisition.

“Big companies are political environments.” Miller shares advice he was given when he sold Definity Health to UnitedHealth Group and became a UHG employee. “Come up with three fights. If you can win two of three, stay. If you lose, you’ve got to leave.” He left, and started Lemhi Ventures.