X0306 4 2021-01-21 0 0001322505 ALBIREO PHARMA, INC. ALBO 0001572002 Horn Patrick Taylor C/O ALBIREO PHARMA, INC. 10 POST OFFICE SQUARE, SUITE 1000 BOSTON MA 02109 0 1 0 0 Chief Medical Officer Common Stock 2021-01-21 4 A 0 5500 0.00 A 9935 D Common Stock 2021-01-22 4 S 0 110 34.62 D 9825 D Stock Option (right to buy) 34.88 2021-01-21 4 A 0 23700 0.00 A 2031-01-20 Common Stock 23700 23700 D Consists of restricted stock units ("RSUs"). Each RSU represents the right to receive one share of common stock upon vesting. The RSUs vest as to 25% of the shares on January 21, 2022, with the remainder vesting in equal installments every three months thereafter beginning on April 21, 2022 and ending on January 21, 2025. Represents 1,622 shares of common stock and 8,313 restricted stock units. Includes 150 shares of common stock acquired under the Albireo Pharma, Inc. 2018 Employee Stock Purchase Plan on November 30, 2020. Shares sold pursuant to a Rule 10b5-1 arrangement established in October 2019 to satisfy tax obligations arising out of the vesting of previously granted restricted stock units. Represents 1,825 shares of common stock and 8,000 restricted stock units. This option vests as to 25% of the shares on January 21, 2022, with the remainder vesting in equal installments every three months thereafter beginning on April 21, 2022 and ending on January 21, 2025. /s/ Jason Duncan, Attorney-in-fact 2021-01-25