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Castlight HealthInvestor Overview

John Doyle, CEO

January 2018

NYSE: CSLT

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Safe Harbor

Statement

This presentation contains forward-looking statements regarding our trends, our strategies and the anticipated performance of our business, including our guidance for the full year of 2018 as to the timing of cash flow and non-GAAP operating break-even and managing certain line items as a percentage of revenue. These statements were made as of January 11, 2018, and reflect management’s views and expectations at that time, and are subject to various risks, uncertainties and assumptions. If this presentation is viewed after January 11, 2018, the information in the presentation may no longer be current or accurate. We disclaim any obligation to update or revise any forward-looking statements.

We provide limited guidance in this presentation, but we will not provide any further guidance or updates on our performance during the quarter unless we do so in a public forum. Please refer to the Company’s October 25, 2017 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. This presentation also includes certain non-GAAP metrics, such as non-GAAP gross profit and margin, operating expenses, and operating loss, that we believe aid in the understanding of historical financial results. A reconciliation to comparable GAAP metrics, on a historical basis, can be found in the appendix section of this presentation.

In addition, please note the close date of the Jiff acquisition was April 3, 2017. Accordingly, the deferred revenue fair value adjustment discussed in this presentation is a preliminary estimate and is subject to change upon the completion of purchase price accounting.

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Castlight Health

• Founded in 2008 | 500+ Employees | HQ in San Francisco

• Leading healthcare navigation SaaS platform attacking an $8B+ TAM

• Platform expanded significantly through predictive analytics

investments and the April 2017 Jiff acquisition

• Key differentiation in ecosystem, integrations, data, and

personalization

250+Customers

$157MARR as of 09/30/17

Break Evenin Q4 2018

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Why Healthcare Navigation?

Restrict

Choice

Align

IncentivesEngage

& Guide

HMOs Consumer-Directed

Health Plans

Healthcare

Navigation

Mid 1990’s TodayMid 2000’s

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The Castlight Total Addressable Market

$8+ Billion

$5 Billion

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Complete Health Navigator

Castlight’s complete health experience in a single app - built just for the HR suite,

personalized for their employees.

The Castlight Health Navigation Platform

Wellbeing Navigator

Drive engagement across an

employer’s entire benefit programs

with Castlight’s personalized,

incentivized benefit navigator.

Care Guidance

Navigator

Everything employees need to make

better care decisions.

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Differentiator: EcosystemConnecting all of an employer’s critical health benefits data partners

Built ecosystem across the health

and wellness spectrum

Breadth of Connectivity Depth of IntegrationsHealth claims, ecosystem partners

and user-generated data drive

deep integrations

VALUABLE

DATA ASSET

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Differentiator: Personalization

Data Recommendations

User Preferences

Claims

Employer

Data Partners

Gathers data from numerous sources in real-time

Builds personalized user profile that evolves over time

Reaches out with best available channel for the message

Engages each employee with personalized campaigns

User Behaviors

Segmentation Engine Recommendation Engine

An intelligent personalization engine that matches employees to the right resources

Program

Behavior

Care Option

Predictive Content

Incentives

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Demo: “Laura”• Type 2 diabetic

• Missed recent glucose tests

Push notification on

smartphone

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App Home Page• Personalized content and

recommendations

Notification to

schedule A1c test

Click-to-call

information for lab on

her care team

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App Home Page• Personalized integrations

and recommendations

HSA vendor

integration

Incentivized,

personalized

ecosystem partner

recommendation

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Quiz to see if Laura

would benefit from her

employer’s employee

assistance program (EAP)

App Home Page• Predictive analytics:

depression is comorbid with

diabetes

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App Benefits Tab• Additional personalized,

incentivized

recommendations

• Breadth of program

integrations (partial list

shown here)

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Case Study

21% reduction in

ER usage

22%reduction in

adv imaging

procedure costs

9% reduction in

office visit

costs

9xincrease in

telehealth usage

Overall, 9% reduction in healthcare costs for Castlight users

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Target HR buyer within large, self-insured employers

Subscription model with three-year contracts

Continue to “land and expand”

Castlight’s Business Model

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Go-To-Market Strategy

Direct + Channel

Sales Strategy

Strategic

Go-to-Market

Relationship +

to Penetrate Early Majority Buyersfor Large, Innovator Buyers

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$78

$110$122

2014 2015 2016 Sep. '17

Annualized Recurring Revenue (ARR)from Subscription

$157MARR as of 09/30/17

$ in M

illions

$45Revenue: $75 $102 >$130 (1)

Significant Growth with High Visibility

(1) FY 2017 guidance as of October 25, 2017.

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2014 2015 2016 Sep. '17

Includes Jiff’s ARR beginning April 3, 2017

$78

$110$122

$157

Strong Platform ARR Traction

ARR,

$ in M

illions

Platform

Transparency

Go-to-market strategy focused on platform sales to new customers and converting

legacy transparency customers to the platform

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($70)($65)

($31)<($31) (1)

2014 2015 2016 2017F 2018F

Non-GAAP Operating Loss

$ in M

illions

Break even

in Q4’18

Acquisition of

Jiff completed

in 1H’17

Steady Progress Toward Break Even

(1) Guidance as of October 25, 2017. Please see the Appendix for a discussion of the Company’s non-GAAP metrics.

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Operating Model

(Non-GAAP, % of Revenue) 3Q’17 Target Range Year Target Achieved

Gross Margin 67% 70% - 75% 2018*

Sales & Marketing 36% 30% - 32% 2018*

Research & Development 35% 12% - 14% -- (1)

General & Administrative 15% 8% - 12% 2018*

Operating Income (19)% 20% - 25% Break-even in 4Q ’18 (2)

Please see the Appendix for a discussion of the Company’s non-GAAP metrics.

* Target achieved in Q4’18

(1) Expect continued discretionary investment above long-term target through at least 2019

(2) Expect to have at least $60 million of cash on the balance sheet at that time

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2018 Strategic Goals

GROWTH

SUSTAINABIL ITY

Continue to scale

platform ARR

Cash flow break

even in Q4 ’18

INNOVATIONInvest to capitalize on

the market opportunity

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Thank you

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Appendix

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Guidance as of October 25, 2017. Please see the Appendix for a discussion of the Company’s non-GAAP metrics.

Initial Range Q3 2017 Update

GAAP Revenue $132mm – $136mm Above $130mm

Non-GAAP Operating (Loss) $ (31)mm – $(35)mm Beat the range

Non-GAAP EPS $(0.24) – $(0.28) Beat the range

Basic & Fully-Diluted Shares Outstanding 125mm – 127mm 125mm – 127mm

Cash Used in Operations Mid-$30mm range Mid-$30mm range

2017 Guidance

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Gross Profit:

Reconciliation of GAAP to Non-GAAP

September 30,

2016

December 31,

2016

March 31,

2017

June 30,

2017

September 30,

2017

Gross profit:

GAAP gross profit subscription $19,879 $23,912 $21,520 $22,128 $23,240

Stock-based compensation 139 139 127 253 258

Amortization of internal-use software 244 244 244 244 244

Amortization of Intangibles - - - 751 751

Acquisition related costs - - - 52 -

Reduction in workforce - - - - -

Non-GAAP gross profit subscription $20,262 24,295 21,891 23,428 24,493

GAAP gross loss professional services $(2,344) $(2,417) $(2,009) $(2,528) $(1,689)

Stock-based compensation 456 493 461 597 342

Acquisition related costs - - 147 17 (4)

Capitalization of internal-use software - - - - -

Reduction in workforce 4 - - - -

Non-GAAP gross loss professional services $(1,884) $(1,924) $(1,401) $(1,914) $(1,351)

GAAP gross profit $17,535 $21,495 $19,511 $19,600 $21,551

Impact of non-GAAP adjustments 843 876 979 1,914 1,591

Non-GAAP gross profit $18,378 $22,371 $20,490 $21,514 $23,142

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Operating Expense:

Reconciliation of GAAP to Non-GAAP

September 30,

2016December 31,

2016

March 31,

2017

June 30,

2017

September 30,

2017

Operating expense:

GAAP sales and marketing $13,143 $13,923 $14,443 $16,575 16,006

Stock-based compensation (2,190) (2,199) (2,154) (2,441) (3,110)

Amortization of Intangibles - - - (448) (448)

Acquisition related costs - - (405) (518) 14

Reduction in workforce (48) - - - -

Non-GAAP sales and marketing $10,905 $11,724 $11,884 $13,168 $12,462

GAAP research and development $10,573 $9,841 $11,071 $15,194 $13,809

Stock-based compensation (1,631) (1,659) (1,790) (2,254) (1,631)

Capitalization of internal-use software - - - - -

Reduction in workforce (18) - - - -

Acquisition related costs - - (267) (126) -

Non-GAAP research and development $8,924 $8,182 $9,014 $12,814 $12,178

GAAP general and administrative $5,338 $6,957 $8,998 $6,766 $10,307

Stock-based compensation (1,236) (1,267) (1,295) (1,169) (1,121)

Amortization of Intangibles - - - (17) (17)

Change in FV of contigent consideration - - - 643 (3,931)

Acquisition related costs - (1,731) (2,340) (899) (126)

Reduction in workforce (10) - - -

Litigation settlement - - (250) - -

Non-GAAP general and administrative $4,092 $3,959 $5,113 $5,324 $5,112

GAAP operating expense $29,054 $30,721 $34,512 $38,535 $40,122

Impact of non-GAAP adjustments (5,133) (6,856) (8,501) (7,229) (10,370)

Non-GAAP operating expense $23,921 $23,865 $26,011 $31,306 $29,752

Operating loss:

GAAP operating loss ($11,519) $(9,226) $(15,001) $(18,935) $(18,571)

Impact of non-GAAP adjustments 5,976 7,732 9,480 9,143 11,961

Non-GAAP operating loss $(5,543) $(1,494) $(5,521) $(9,792) $(6,610)

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To supplement Castlight Health’s financial statements presented in accordance with generally accepted

accounting principles (GAAP), we also use and provide investors and others with non-GAAP measures of certain

components of financial performance, including non-GAAP gross profit and margin, non-GAAP operating expense,

non-GAAP operating loss, non-GAAP net loss and non-GAAP net loss per share. Non-GAAP gross profit and margin,

non-GAAP operating expense, non-GAAP operating loss and non-GAAP net loss exclude stock-based compensation,

litigation settlement, charges related to a reduction in workforce, amortization of intangibles, capitalization and

amortization of internal-use software, changes in fair value of contingent consideration and charges related to

the acquisition and the associated tax impact of these items, where applicable.

We believe that these non-GAAP financial measures provide useful supplemental information to investors and

others, facilitate the analysis of the Company’s core operating results and comparison of operating results across

reporting periods, and can help enhance overall understanding of the Company’s historical financial performance.

We have provided a reconciliation of each non-GAAP financial measure to the most directly comparable GAAP

financial measure, except that we have not reconciled our non-GAAP operating loss and net loss per share

guidance for the full year 2017 to comparable GAAP operating loss and net loss per share guidance because we do

not provide guidance for stock-based compensation expense, capitalization and amortization of internal-use

software, changes in fair value of contingent consideration and charges related to the acquisition, which are

reconciling items between GAAP and non-GAAP operating loss. The factors that may impact our future stock-

based compensation expense and capitalization and amortization of internal-use software are out of our control

and/or cannot be reasonably predicted, and therefore we are unable to provide such guidance without

unreasonable effort. Factors include our market capitalization and related volatility of our stock price and our

inability to project the cost or scope of internally produced software and charges related to the proposed

acquisition for the year.

These non-GAAP financial measures should be considered in addition to, not as a substitute for or in isolation

from, measures prepared in accordance with GAAP.

Further, these non-GAAP measures may differ from the non-GAAP information used by other companies, including

peer companies, and therefore comparability may be limited. Castlight Health encourages investors and others to

review the Company’s financial information in its entirety and not rely on a single financial measure.