Castlight Health, Inc. Conference Call to Review First Quarter 2016 Results Scheduled for May 10 at 2 p.m. PT

April 18, 2016

SAN FRANCISCO April 18, 2016 – Castlight Health, Inc. (NYSE: CSLT), a leading health benefits platform provider, today announced that it has scheduled a conference call to review its first quarter 2016 results (ended March 31, 2016) for Tuesday, May 10, 2016 at 2:00 p.m. Pacific Time (5:00 p.m. Eastern Time).

To listen to the conference call live, dial (877) 201-0168. The conference ID number is 86434239. Please dial in at least five minutes before the scheduled start time. A live webcast can be accessed at www.castlighthealth.com in the Investor Relations section.

A replay of the call will be available, beginning at approximately 5:00 p.m. Pacific Time on May 10, 2016 for one week, at (855) 859-2056, and archived via webcast at www.castlighthealth.com. The replay access code is 86434239.

A press release highlighting the company’s results will be issued in advance of the conference call and will be accessible at www.castlighthealth.com in the Investor Relations section.

About Castlight Health

Our mission is to empower people to make the best choices for their health and to help companies make the most of their health benefits. We offer a health benefits platform that engages employees to make better healthcare decisions and guide them to the right program, care, and provider. The platform also enables benefit leaders to communicate and measure their programs while driving employee engagement with targeted, relevant communications. Castlight has partnered with more than 190 customers, spanning millions of lives, to improve healthcare outcomes, lower costs, and increase benefits satisfaction.

For more information visit www.castlighthealth.com. Follow us on Twitter and LinkedIn and Like us on Facebook.

Investor Contact:

Ann Hickey

[email protected]

415-829-1400

Media Contact:

Jim Rivas

[email protected]

415-829-1568

Copyright 2016 Castlight Health, Inc. Castlight Health® is the registered trademark of Castlight Health, Inc. Other company and product names may be trademarks of the respective companies with which they are associated.