X0306 4 2015-09-10 0 0000861878 STERICYCLE INC SRCL 0001360147 Chen Thomas F 28161 N. KEITH DRIVE LAKE FOREST IL 60045 1 0 0 0 Depositary Shares 2015-09-10 4 P 0 6000 100.00 A 2015-09-10 2018-09-15 Common Stock 3523 6000 D This form reports the purchase by the undersigned of 6,000 depositary shares, each representing a 1/10th interest in a share of the issuer's 5.25% Series A Mandatory Convertible Preferred Stock. The conversion rate for each depositary share will be not more than 0.73394 shares of common stock and not less than 0.58716 shares of common stock depending on the applicable market value of the common stock. Represents the minimum number of shares of common stock into which the 6,000 depositary shares are convertible. Represents the purchase price for each depositary share. /s/ Thomas F. Chen 2015-12-29