#1 Represents distribution of Jacobs common stock upon vesting of performance stock units awarded on November 17, 2021 pursuant to the Company's Stock Incentive Plan.

#2 The number of performance stock units that vested, and therefore the number of shares of Jacobs common stock issued upon vesting, represents 63.9% of the number of performance stock units initially awarded, with such percentage based on the Company's earnings per share (EPS) growth over the three-year performance period.

#3 .The number of performance stock units that vested, and therefore the number of shares of Jacobs common stock issued upon vesting, represents 52.0% of the number of performance stock units initially awarded, with such percentage based on the Company's average return on invested capital (ROIC) over the three-year performance period.

#1 The sale was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 8, 2023.

#1 Represents the receipt of restricted stock units pursuant to the Company's Stock Incentive Plan. Each restricted stock unit represents the right to receive one share of Jacobs common stock. The restricted stock unit vests in four equal annual installments beginning on the first anniversary of grant date.

#2 The number of shares included in respect of previously reported grants of restricted stock units pursuant to the Company's Stock Incentive Plan was increased to reflect an equitable adjustment in connection with the spin-off distribution of the Company's Critical Mission Solutions and Cyber & Intelligence government services businesses and the merger of these businesses with Amentum Parent Holdings LLC.