Where is the incentive to deny legitimate claims?
https://www.healthcare.gov/appeal-insurance-company-decision...
Although, even with those fraudulent denials, Cigna's profit margins are suffering:
https://www.macrotrends.net/stocks/charts/CI/cigna-group/net...
Wonder if they went into too much debt to buy Express Scripts.
Because they want to be competitive and gain customers.
Which would you sign up for? Insurance that costs $800/month or $1200/month?
But yes, there is an intense economy-of-scale that produces relatively few insurance companies.
(Maybe eventually only one.)
There are quite a few regional insurance companies. Like here in Utah a big name is Selecthealth, but no one else will have heard it.
National carriers are a safer/easier choice for employers who have a distributed workforce.
Ideally, everyone in the US would have to buy health insurance from healthcare.gov, and can choose whoever they want with zero input from their employer.
Every hospital (public or private) must follow the prices decided by the Confederation, and every health insurance must reimburse following the same prices, not more and not less.
And it works quite well I'd say