CASTLIGHT HEALTH, INC. (NYSE:CSLT) Files An 8-K Other Events

As previously announced, Castlight Health, Inc. (Castlight)
entered into an Agreement and Plan of Merger and Reorganization
(the Merger Agreement) with Neptune Acquisition Subsidiary, Inc.,
a Delaware corporation and wholly owned subsidiary of Castlight
(Merger Sub), Jiff, Inc., a Delaware corporation (Jiff) and
Fortis Advisors LLC, as the Stockholders Agent, to which Merger
Sub will merge with and into Jiff with Jiff surviving the merger
as a wholly owned subsidiary of Castlight (the Merger).

The purpose of this Current Report on Form 8-K is to update the
joint proxy statement/prospectus/information statement included
in the Registration Statement on Form S-4, file No. 333-215861
filed by Castlight with the Securities and Exchange Commission
(SEC) and declared effective by the SEC on February 14, 2017,
relating to the Merger. The joint proxy
statement/prospectus/information statement was first mailed to
stockholders of Castlight on February 24, 2017.

Following the announcement of the execution of the Merger
Agreement, on March 1, 2017, a purported class action lawsuit was
filed in the United States District Court for the District of
California (Kromphold v. Castlight Health, Inc., et al. Case No.
3:17-cv-1081) asserting a claim for violations of Sections 14(a)
and 20(a) of the Securities Exchange Act of 1934, as amended,
against Castlight and its directors. The complaint alleges, among
other things, that Castlight and its board of directors
disseminated a proxy statement that misrepresented or omitted
material information concerning the proposed Merger.

Castlight believes that the lawsuit is without merit and believes
that no further disclosure is required under applicable laws;
however, to avoid the risk of the litigation delaying or
adversely affecting the Merger and to minimize the expense of
defending the litigation related to the Merger, the defendants
have agreed to make the supplemental disclosures related to the
Merger as set forth herein. As a result of the supplemental
disclosures set forth herein, the named plaintiff in the pending
lawsuit has concluded that the claims in the lawsuit have been
mooted, has determined not to seek to enjoin the special meeting
of Castlight stockholders to vote on the Merger, and will dismiss
the lawsuit with prejudice.

Nothing in this Current Report on Form 8-K shall be deemed an
admission of the legal necessity or materiality under applicable
laws of any of the supplemental disclosures set forth herein.

SUPPLEMENT TO DEFINITIVE JOINT PROXY
STATEMENT/PROSPECTUS/INFORMATION STATEMENT

Set forth below are supplemental disclosures to the definitive
joint proxy statement/prospectus/information statement. This
supplemental information should be read in conjunction with the
definitive joint proxy statement/prospectus/information
statement, which should be read in its entirety.

The fourth bullet in the answer to the question Why are Castlight
and Jiff proposing the merger? on page iii in the section
entitled Questions and Answers About the MergerGeneral Questions
and Answers is deleted in its entirety and replaced with the
following:

the likelihood and timing of the cost savings, related expenses
and revenue synergies;

The paragraph beginning On October 14, 2016, on page 57 of the
definitive proxy statement/prospectus/information statement in
the section entitled The MergerBackground of the Merger is
deleted in its entirely and replaced with the following:

On October 14, 2016, the Special Committee authorized Mr. Doyle
to present to Jiff a preliminary term sheet for the potential
acquisition of Jiff by Castlight in an all-stock transaction,
which Mr. Doyle then delivered to Mr. Newell. Mr. Newell, James
Currier, a member of the Jiff Board, Mr. Doyle and Giovanni
Colella subsequently attended an industry conference and had
several conversations regarding potential changes to the proposed
terms, primarily focused on the amount of consideration,
structure of the acquisition, indemnification and potential
leadership structure of a combined company.

The following sentence is added at the end of the paragraph
beginning On October 17, 2016, on page 58 of the definitive proxy
statement/prospectus/information statement in the section
entitled The MergerBackground of the Merger:

Representatives from the key Castlight customer responded
positively to the potential combined offering from Jiff and
Castlight.

The paragraph beginning On November 19, 2016, on page 58 of the
definitive proxy statement/prospectus/information statement in
the section entitled The MergerBackground of the Merger is
deleted in its entirely and replaced with the following:

On November 19, 2016, Mr. Doyle delivered a revised term sheet to
Mr. Newell, which included the terms of the Earnout.

The paragraph beginning On November 21, 2016, on page 59 of the
definitive proxy statement/prospectus/information statement in
the section entitled The MergerBackground of the Merger is
deleted in its entirely and replaced with the following:

On November 21, 2016, Jiff provided comments on the term sheet
and Mr. Newell and Mr. Doyle had several telephone calls to
discuss the term sheet. Between that date and November 27, 2016,
based on input from their respective constituencies,
representatives of Fenwick and Gunderson Dettmer negotiated the
provisions of the term sheet, including indemnification and which
party would pay transaction expenses and in what amount.

The fourth bullet on page 62 of the definitive proxy
statement/prospectus/information statement in the section
entitled The MergerCastlights Reasons for the Merger;
Recommendation of the Special Committee of the Castlight Board is
deleted in its entirety and replaced with the following:

the likelihood and timing of the cost savings, related expenses
and revenue synergies expected to result from the proposed merger
(while Castlight believes such cost savings and synergies are
likely, Castlight has not estimated or otherwise quantified
them);

The paragraph beginning As the Special Committee was aware, on
page 73 of the definitive proxy statement/prospectus/information
statement in the section entitled The MergerOpinion of Castlights
Financial AdvisorCertain Informational FactorsMiscellaneous is
deleted in its entirely and replaced with the following:

As the Special Committee was aware, Allen Company previously
provided investment banking services to Castlight in connection
with its initial public offering in March 2014. Although Allen
Company did not provide investment banking services to Castlight
unrelated to the merger for which Allen Company received
compensation during the past two years, Allen Company in the
future may provide such services to Castlight, for which services
Allen Company may receive compensation.

The table entitled Castlight-Jiff Management Forecasts and the
paragraph beginning Non-GAAP operating loss is defined as GAAP
operating loss, following such table on page 75 of the definitive
proxy statement/prospectus/information statement in the section
entitled The MergerCertain Prospective Financial Information
Relating to Castlight and Jiff are deleted in their entirety and
replaced with the following:

Non-GAAP operating loss is defined as GAAP operating loss,
adjusted to exclude the estimated effects of stock-based
compensation, charges related to reduction in workforce,
litigation settlement, acquisition costs and amortization of
internal use software. New Bookings (Annual Contract Value) is
defined as the aggregate amount of (a) non-contingent
professional services fees and subscription fees payable by any
customer during the first 12 months of a 2017 Jiff contract,

net of any associated third party costs for market place products
and (b) contingent professional and subscription fees earned
during the year. Non-GAAP EBITDA is defined as net loss, adjusted
to exclude the estimated effects of depreciation and
amortization, interest income (expense), net, provision for
income taxes and stock-based compensation.

Non-GAAP unlevered after-tax free cash flow is defined as
non-GAAP EBITDA, as adjusted to include the estimated effects of
depreciation and amortization, stock-based compensation and
taxes, plus depreciation and amortization, less changes in
working capital and less capital expenditures, and for purposes
of this calculation, stock-based compensation was treated as a
cash expense. Non-GAAP unlevered after-tax free cash flow for
Jiff for 2017 through 2019 was calculated as follows (in
millions):

* Numbers do not total due to rounding.

Forward Looking Statements

This document contains forward-looking statements that are not
purely historical regarding Castlights or its managements
intentions, beliefs, plans, expectations and strategies for the
future, including those relating to the prospective financial
information of Jiff. Because such statements deal with future
events, they are subject to various risks and uncertainties, and
actual results could differ materially from Castlights current
expectations. Factors that could cause actual results to differ
materially include risks and uncertainties such as those relating
to the ability of the parties to complete the proposed
transaction, obtaining Castlight and Jiff stockholder approval
and any required regulatory clearances, and customer and partner
reception to the proposed transaction. Readers should also refer
to the section entitled Risk Factors in Castlights most recent
reports on Form 10-K and Form 10-Q and other documents of
Castlight on file with the SEC.

IMPORTANT ADDITIONAL INFORMATION WILL BE FILED WITH THE SEC

In connection with the proposed transaction between Castlight and
Jiff, Castlight has filed a registration statement on Form S-4
with the SEC (Registration Statement No. 333-215861), and this
registration statement, as amended, was declared effective by the
SEC on February 14, 2017. This registration statement contains a
joint proxy statement/prospectus/information statement and
relevant materials concerning the proposed transaction. Castlight
and Jiff mailed the definitive joint proxy
statement/prospectus/information statement to their respective
stockholders on February 24, 2017. Additionally, Castlight
intends to file with the SEC other relevant materials in
connection with the proposed transaction. STOCKHOLDERS OF
CASTLIGHT AND JIFF ARE URGED TO READ ALL RELEVANT DOCUMENTS FILED
WITH THE SEC, INCLUDING THE DEFINITIVE JOINT PROXY
STATEMENT/PROSPECTUS/INFORMATION STATEMENT, BECAUSE THEY WILL
CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION.
Investors and security holders will be able to obtain the
documents free of charge at the SECs web site,
http://www.sec.gov. Documents will also be available for free
from Castlight at www.castlighthealth.com.

This communication shall not constitute an offer to sell or the
solicitation of an offer to sell or the solicitation of an offer
to buy any securities, nor shall there be any sale of securities
in any jurisdiction in which such offer, solicitation or sale
would be unlawful prior to registration or qualification under
the securities laws of any such jurisdiction. No offering of
securities

in connection with the proposed transaction shall be made except
by means of a prospectus meeting the requirements of Section 10
of the Securities Act of 1933, as amended.

Castlight and its executive officers and directors may be deemed
to be participants in the solicitation of proxies from Castlights
stockholders with respect of the matters relating to the proposed
transaction. Jiff and its officers and directors may also be
deemed a participant in such solicitation. Information regarding
any interest that Castlight, Jiff or any of the executive
officers or directors of Castlight or Jiff may have in the
proposed transaction with Jiff is included in the joint proxy
statement/prospectus/information statement that Castlight has
filed with the SEC in connection with its stockholder vote on
matters relating to the proposed transaction. Information about
the directors and executive officers of Castlight, including
their respective interest in security holding of Castlight, is
set forth in the proxy statement for Castlights 2016 Annual
Meeting of Stockholders, which was filed with the SEC on April
29, 2016. Stockholders may obtain additional information
regarding the interest of such participants by reading the
definitive joint proxy statement/prospectus/information statement
regarding the proposed transaction when it becomes available.
These documents can be obtained free of charge from the sources
indicated above.