Castlight Health, Inc. Conference Call to Review First Quarter 2015 Results Scheduled for May 6 at 2 p.m. PT

April 16, 2015

SAN FRANCISCO — April 16, 2015 — Castlight Health, Inc. (NYSE:CSLT), a pioneer of the Enterprise Healthcare Cloud, today announced that it has scheduled a conference call to review its first quarter 2015 results (ended March 31, 2015) for Wednesday, May 6, 2015 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 29812154. Please dial in at least five minutes before the scheduled start time. A live webcast can be accessed at www.castlighthealth.com.

A replay of the call will be available, beginning at approximately 5:00 p.m. Pacific Time on May 6, 2015 for one week, at (855) 859-2056, and archived via webcast at www.castlighthealth.com. The replay access code is 29812154.

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 Castlight Health, Inc. (NYSE:CSLT) is a leader in Enterprise Healthcare Management. We believe great healthcare builds great business and U.S. enterprises can gain control over the $620 billion spent annually on healthcare, transforming a crippling cost into a strategic business advantage. Recognized as a top 2014 software platform by the HR Technology Conference & Exposition, the Castlight Enterprise Healthcare Cloud enables employers to understand and manage all their healthcare investments while helping employees make the best possible healthcare decisions. Castlight is a great place to work, honored with a Glassdoor Employees’ Choice award and recognized by Rock Health for Diversity in Leadership. For more information visit www.castlighthealth.com. Follow us on Twitter and LinkedIn and Like us on Facebook. Source: Castlight Health.

Investor Contact:

Charles Butler

[email protected]

415-829-1400

Media Contact:

Jim Rivas

[email protected]

415-515-8780

Copyright 2015 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.