Mark Morgan, 48, president of the company's California business since 2013, will depart April 24.

Conservative objections over spending are raising doubts over whether the U.S. Senate can quickly approve legislation fixing the Medicare physician payment system, in a possible setback for Republicans keen to show they can get things done.

As consumers increasingly are being asked to pay a larger share of their health bills, a coalition of insurers, pharmaceutical companies, and provider and consumer advocacy groups launched Thursday a new push for greater transparency regarding the actual costs of services.

U.S. spending on prescription medicines jumped 13 percent to $374 billion in 2014, the biggest percentage increase since 2001, as demand surged for expensive new breakthrough hepatitis C treatments, a report released on Tuesday showed.

By weaving together a hodgepodge of patient information, clinical data and scientific know-how, California officials hope to create a sort of "Google Maps for health" to drive the right therapies to the right people at the right time.

The rate of uninsured Americans fell to 11.9% in the first quarter of 2015, down one percentage point from the end of 2014, according to a Gallup survey.