CASTLE BIOSCIENCES INC

The Director Compensation Policy provides for equity grants, beginning with annual grants to be made following the Annual Meeting.

Initial Grant for New Directors: Upon joining the Board, non-employee directors will automatically receive an initial equity grant (the “Initial Grant”) valued at $400,000, consisting of a RSU award covering a number of shares of common stock calculated by dividing $400,000 by the average of the closing prices of our common stock for each trading day within the 30 calendar days prior to the grant date (such price, the “Average Price”), rounded down to the nearest whole share (the “Total Initial Shares”). In the event that more than one non-employee director is elected or appointed within a single calendar year, for each non-employee director elected or appointed after the first election or appointment of a non-employee director in such calendar year (each, a “Subsequent Director”), if the Average Price calculated for purposes of determining the Total Initial Shares underlying the Initial Grant for a Subsequent Director has not increased or decreased by more than 10% compared to the Average Price calculated for purposes of determining the Total Initial Shares underlying the Initial Grant for the first non-employee director elected or appointed in that same calendar year (the “First Director”), then the Total Initial Shares underlying the Initial Grant for such Subsequent Director shall be equal to the Total Initial Shares calculated for the First Director. The shares subject to the Initial Grant will vest in a series of three successive equal annual installments over the three-year period measured from the grant date.

Annual Grant: At the close of business on the date of each annual meeting of stockholders, beginning with the Annual Meeting, each of our non-employee directors will automatically receive an annual equity grant (the “Annual Grant”) valued at $260,000, consisting of an RSU award covering a number of shares of common stock calculated by dividing $260,000 by the Average Price, rounded down to the nearest whole share. The shares subject to the Annual Grant vest in full on the earlier of a) the one-year anniversary of the date of grant or b) the day immediately preceding the next annual meeting following the date of grant. In addition, the Director Compensation Policy provides for (i) a six-month service period by any new non-employee director that must be satisfied before such new non-employee director becomes eligible to receive an Annual Grant and (ii) proration of a non-employee director’s first Annual Grant based on the number of completed months served, subject to the six-month service period required by any new non-employee director for eligibility to receive an Annual Grant.

Each Initial Grant and Annual Grant will vest subject to the non-employee director’s continuous service to us, provided that each such grant will vest in full upon a change in control (as defined in the 2019 Plan).