X0306 4 2018-07-27 1 0001433714 CASTLIGHT HEALTH, INC. CSLT 0001365607 OAK INVESTMENT PARTNERS XII L P 901 MAIN AVENUE SUITE 600 NORWALK CT 06851 0 0 1 0 Common Stock 2018-07-27 4 J 0 5958872 D 5958872 I See Note (2) On July 27 2018, Oak Investment Partners XII, L.P., a Delaware limited partnership, ("Oak XII") made an in-kind distribution, without any additional consideration, of common stock of the Issuer to the limited partners of Oak XII. Represents shares directly owned by Oak XII. Oak Associates XII, LLC, a Delaware limited liability company ("Oak Associates") and the General Partner of Oak XII, may be deemed to beneficially own these shares. Remarks: This Form 4 report is being filed by Oak XII, and Oak Associates (together the "Reporting Persons"). However, each Reporting Person disclaims the existence of a "group" and disclaims beneficial ownership (as defined in Rule 16a-1(a)(2)) of any securities (except to the extent of such Reporting Person's pecuniary interest in such securities) other than any securities reported herein as being dirctly owned by such Reporting Person, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of any such securities for purposes of Section 16 or for any other purpose. /s/ Oak Associates XII, LLC, general partner of Oak Investment Partners XII, Limited Partnership 2018-10-09 /s/ Oak Associates XII, LLC 2018-10-09