Payer

Health plans face a myriad of challenges this year, like waning market stability in ACA health exchanges, looming repeal and replacement of the health law and a surge toward care efficiency.

Texas has the highest rate of uninsured individuals in the nation, followed by Mississippi and Oklahoma, according to a Gallup-Healthways poll.

The five largest U.S. health insurers — Aetna, Anthem, Cigna, Humana and UnitedHealth Group — saw a range of financial results in the fourth quarter of 2016.

Louisville, Ky.-based Humana reported a fourth quarter consolidated revenue of $12.9 billion in 2016, falling 4 percent from $13.4 billion in the same period last year.

Colorado's health insurance exchange reported a 12 percent increase in health plan signups during the three months of open enrollment for 2017 coverage compared to last year.

Eagan, Minn.-based Blue Cross and Blue Shield of Minnesota named Tom Vanderheyden, former CEO of UnitedHealth Group subsidiary Harken Health, president of diversified business.

As Republican lawmakers continue efforts to repeal and replace the ACA, Minnesota's insurance market is going through various changes.

Tampa, Fla.-based WellCare Health Plans reported net income of $242.1 million for full-year 2016, a roughly 104 percent increase from its net income of $118.6 million last year.

Here are 25 things to know about UnitedHealth Group, which operates the largest single health insurer in the U.S.

Three of the nation's largest health insurers are contemplating what their 2018 ACA exchange footprints will look like in light of potential changes to federal regulations and market stability.