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This presentation contains forward-looking statements regarding our trends, our strategies and the anticipated performance of our business, including our guidance for the second quarter and full year of 2016. These statements reflect management’s current views and expectations, and are subject to various risks, uncertainties and assumptions.

Please refer to the press release and the risk factors included in the company’s filings with the Securities and Exchange Commission, for discussion of important factors that may cause actual events or results to differ materially from those contained in our forward-looking statements.

Forward-looking statements made in this presentation are being made as of the date of this presentation. After the date of this presentation, the information contained in this presentation may no longer be current or accurate. We disclaim any obligation to update or revise any forward-looking statements. This presentation contains guidance but we will not provide any further guidance or updates on our performance during the quarter unless we do so in a public forum.

This presentation also includes certain non-GAAP metrics, such as non-GAAP gross margin, operating expenses, net loss and net loss per share, that we believe aid in the understanding of our financial results. A reconciliation to comparable GAAP metrics, on a historical basis, can be found in the earnings release dated May 10, 2016, which is available on our website and as an exhibit to the form 8-K filed with the SEC.

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To people to make the best decisions for

their health and companies make the most of their

health benefits

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Our health benefits platform

to make

better healthcare decisions and

to

communicate and evaluate their benefits

programs

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7 Confidential Source: Centers for Medicare and Medicaid Services (2015), The Institute of Medicine (2013), and BAML 2013 CFO Outlook Report, Kaiser Family Foundation; 2014 Employer Health Benefits Survey; U.S. Census; U.S. Bureau of Labor Statistics

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4%

13%

24%

37%

2006A 2010A 2015A 2018E

Covered Workers Enrolled in a HDHP (%)

$8K

$3K

$13K

$5K

EmployerPremium

(4% CAGR)

EmployeeContribution

(6% CAGR)

From 2005 to 2015, employer premiums and employee contributions have increased 54% and

83%, respectively

Adoption of HDHP among large employers

is expected to grow significantly in the next

1 – 3 years

Source: Kaiser Family Foundation; 2014 Employer Health Benefits Survey; HDHP: High Deductible Health Plan; Kaiser Family Foundation; 2015 Employer Health Benefits Survey: http://kff.org/report-section/ehbs-2015-summary-of-findings/; (2) Goldman Sachs 2015 Employer Benefit Manager Survey

62%

79% 86%

96% 94%

In 2015, 94% of firms with 5,000+ workers

were self insured versus 62% in 1999

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Shifting emphasis from wellness to employee well-being

Expanded set of vendor programs sold directly into the HR suite

Cost pressure and regulatory demands due to ACA legislation

Increased administrative burden and compliance requirements

Expectation to leverage big data to drive more meaningful analytics

Increasing strategic responsibility and need for tailored programs

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Of employees don’t fully understand their

healthcare benefits

Source: 2015 Aflac Workforces Report; SHRM.org; Castlight Health research

Of employees use most benefit programs

Of employers feel they lack data on benefit

program effectiveness

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Targeted, timely communications to

employees to better decisions

Simple, integrated way to help

benefits

Real-time into

engagement with benefits and programs

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Medical • Rx • Dental • BH

SSO • HSA

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ACME Telehealth

http://www.acmehealth.com

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5% Market

Penetration

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Employees opting for

HDHPs

return

rate with an average of 12

page views per login

Decrease in

healthcare cost trend

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Return to

Castlight within 90 days

Engagement with Castlight

Savings as much as

$16K on a single

surgical procedure

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Transparency Solutions

Engagement Solutions

4

4

4 7

7

2

2

2

7

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$13

$75

2013 2015Revenue

$47

$110

2013 2015ARR

-32%

59%

2013 2015NON-GAAP GROSS MARGIN (%)

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SAP and CSLT announced plans for a multi-pronged business

alliance:

• SAP HCM’s business and CSLT plan to enter into a distribution relationship

• CSLT plans to participate in SAP’s new Connected Health platform

• SAP made a ~$18M minority investment in CSLT

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Except Per Share Data

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