X0306 4 2021-03-01 0 0001515673 Ultragenyx Pharmaceutical Inc. RARE 0001780113 Harris Erik 60 LEVERONI COURT NOVATO CA 94949 0 1 0 0 EVP & Chief Commercial Officer Common Stock 2021-03-01 4 A 0 5500 0.00 A 26354 D Common Stock 2021-03-01 4 A 0 4636 0.00 A 30990 D Common Stock 2021-03-01 4 S 0 2470 138.17 D 28520 D Common Stock 2021-03-02 4 S 0 707 138.16 D 27813 D Stock Option (Right to Buy) 142.47 2021-03-01 4 A 0 11000 0.00 A 2031-03-01 Common Stock 11000 11000 D Award of Restricted Stock Units ("RSUs") under the Company's 2014 Incentive Plan. The RSUs shall vest with respect to 1/4th of the underlying shares on each anniversary of the grant date, such that the RSUs are fully vested on the fourth anniversary of the grant date. Represents 1,530 shares of common stock and 3,106 RSUs into which previously granted performance stock units were converted on March 1, 2021 upon certification of the performance metric. The RSUs will fully vest on March 1, 2022. Represents shares sold to pay required tax withholdings due to the vesting of RSUs. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $138.16 to $138.20 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The sales reported on this row were effected pursuant to a trading plan adopted by the Reporting Person pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended. Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions. On the first anniversary of the grant date of the option (the "Option Anniversary Date"), 1/4th of the shares initially subject to the option shall vest; thereafter, 1/48th of the shares initially subject to the option shall vest on each month as measured from the Option Anniversary Date. /s/ Karah Parschauer, attorney-in-fact 2021-03-03