PSN

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

The price reported in Column 4 is a weighted-average price. The reporting person undertakes to provide 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 purchased at each separate price within the range set forth in this footnote.

These shares were purchased in multiple transactions at prices ranging from $50.20 to $51.09.

The price reported in Column 4 is a weighted-average price. The reporting person undertakes to provide 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 purchased at each separate price within the range set forth in this footnote.

These shares were purchased in multiple transactions at prices ranging from $51.24 to $51.81.

The price reported in Column 4 is a weighted-average price. These shares were purchased in multiple transactions at prices ranging from $49.56 to $50.36. The reporting person undertakes to provide 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 purchased at each separate price within the range set forth in this footnote.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest on April 1, 2029 and have no expiration date.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in two equal annual installments beginning on March 1, 2027 and have no expiration date.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in three equal annual installments beginning on March 10, 2027 and have no expiration date.

Represents an award of RSUs. Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in three equal annual installments beginning on March 10, 2027 and have no expiration date.

The reporting person was previously granted an award of performance stock units (PSUs), which vest in the form of common stock based upon the Issuer's performance against certain strategic objective goals. On February 20, 2026, the Compensation Committee of the Issuer's Board of Directors determined that the strategic objective goals had been met, resulting in the vesting of these shares.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in four equal annual installments beginning on March 10, 2027 and have no expiration date.

Includes 276 shares of common stock automatically purchased on behalf of the reporting person pursuant to the terms of the Parsons Employee Stock Purchase Plan.

The reporting person was previously granted an award of performance stock units (PSUs), which vest in the form of common stock based upon the Issuer's performance against certain strategic objective goals. On February 20, 2026, the Compensation Committee of the Issuer's Board of Directors determined that the strategic objective goals had been met, resulting in the vesting of these shares.

Represents an award of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in three equal annual installments beginning on March 10, 2027 and have no expiration date.

Includes 289 shares of common stock automatically purchased on behalf of the reporting person pursuant to the terms of the Parsons Employee Stock Purchase Plan.

The reporting person was previously granted an award of performance stock units (PSUs), which vest in the form of common stock based upon the Issuer's performance against certain strategic objective goals. On February 20, 2026, the Compensation Committee of the Issuer's Board of Directors determined that the strategic objective goals had been met, resulting in the vesting of these shares.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units, subject to any deferral election made by the insider.

Represents an award of fully vested restricted stock units. Vested shares will be delivered pursuant to the terms and conditions set forth in the applicable grant notice for such restricted stock units.