Owing in part to Centene's willingness to play rescuer, only 2 counties nationwide will lack an ACA insurance option in 2018.

Odd as it may seem, given how well the decision to bail on the ACA has paid off, UnitedHealth should at least consider an eventual return.

The president's new health care strategy of repeal minus fast replacement ratchets up uncertainty once again.

Health care stocks in the Russell 3000 index of the largest U.S. companies are outperforming the index as a whole since the election. A few stocks with ACA exposure are down since the election, but many more are up.

Donald Trump has gone from terrifying the pharma industry with pricing criticism to increasingly conspicuous silence. A White House budget plan released this week essentially ignored drug pricing.

UnitedHealth Group Inc. is out on Obamacare but in on the government.

The fight over the ACA and individual exchanges concerns a relatively small portion of the market -- but the GOP's proposed shift in tax policy would have a far bigger impact on insurers and employers.

While other big insurers were relatively slow to pull back from the ACA's individual insurance exchanges as their losses mounted, UnitedHealth started taking steps to limit its losses in late 2015 and announced a near-total exit in April 2016.