X0306 4 2017-02-17 0 0001433714 CASTLIGHT HEALTH, INC. CSLT 0001679464 Nolan Mangini Siobhan C/O CASTLIGHT HEALTH, INC. 150 SPEAR ST., SUITE 400 SAN FRANCISCO CA 94105 0 1 0 0 CFO & Treasurer Class B Common Stock 2017-02-17 4 M 0 578 0 A 33419 D Class B Common Stock 2017-02-21 4 S 0 270 3.45 D 33149 D Restricted Stock Units 0 2017-02-17 4 M 0 578 0 D Class B Common Stock 578 4047 D Release and settlement of restricted stock units ("RSUs") granted to the Reporting Person on November 17, 2014, the grant of which was previously reported by the Reporting Person on a Form 3. Represents shares sold by the Reporting Person to cover taxes and fees due upon the release and settlement of the RSU's. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees. Each RSU represents a contingent right to receive 1 share of the Issuer's Class B common stock upon settlement for no consideration. 25% of the RSUs vested on November 17, 2015 and the remainder will vest quarterly over three years thereafter in equal installments. Shares of the Issuer's Class B common stock will be delivered to the Reporting Person following vesting, at which time shares will be sold by the Reporting Person to cover any tax withholding obligations. /s/ Jennifer Chaloemtiarana, by power of attorney 2017-02-21