PRIM · Primoris Services Corp

These transactions were the result of the automatic reinvestment of dividends received on shares of issuer common stock pursuant to a broker-sponsored dividend reinvestment plan.

Based on information provided by the investment advisor; additional information, including the price range, if any, is unavailable.

Sale made by the reporting person as part of an annual asset diversification strategy.

These shares were sold in multiple transactions at prices ranging from $128.17 to $129.10 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale made by the reporting person as part of an annual asset diversification strategy.

These shares were sold in multiple transactions at prices ranging from $126.14 to $127.06 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale made by the reporting person as part of an annual asset diversification strategy.

These shares were sold in multiple transactions at prices ranging from $127.15 to $128.08 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale made by the reporting person as part of an annual asset diversification strategy.

These shares were sold in multiple transactions at prices ranging from $129.24 to $130.24 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale made by the reporting person as part of an annual asset diversification strategy.

These shares were sold in multiple transactions at prices ranging from $125.06 to $126.02 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Sale made by the reporting person as part of an annual asset diversification strategy.

This amended Form 4 amends such filing to report the transaction code in Column 3 as "P".

These shares were purchased in multiple transactions at prices ranging from $127.81 to $128.00 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

These shares were sold in multiple transactions at prices ranging from $119.01 to $120.00 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

These shares were sold in multiple transactions at prices ranging from $120.03 to $120.60 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

These shares were sold in multiple transactions at prices ranging from $118.00 to $119.00 per share, inclusive. The holder undertakes to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon written request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during March 2026, resulting in a grant of 268 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.

These transactions were the result of the automatic reinvestment of dividends received on shares of issuer common stock pursuant to a broker-sponsored dividend reinvestment plan.

Based on information provided by the investment advisor; additional information, including the price range, if any, is unavailable.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On April 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Withholding of common stock to satisfy reporting person's tax obligation upon the settlement of vested restricted stock units.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On April 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On April 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Withholding of common stock to satisfy reporting person's tax obligation upon the settlement of vested restricted stock units.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On April 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

These shares are owned directly by the Kinch Family Trust and indirectly by Jeremy Kinch, as trustee of the trust.

Amount of securities beneficially owned includes 25,534 shares previously transferred to the Kinch Family Trust which were inadvertently reported in prior periods as directly owned.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Withholding of common stock to satisfy reporting person's tax obligation upon the settlement of vested restricted stock units and performance stock units.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Withholding of common stock to satisfy reporting person's tax obligation upon the settlement of vested restricted stock units and performance stock units.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

These shares represent the acquisition of common stock resulting from the vesting of earned performance stock units issued under an equity incentive plan of the Company.

Withholding of common stock to satisfy reporting person's tax obligation upon the settlement of vested restricted stock units and performance stock units.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in theCompany's discretion.

The restricted stock units vest 25% on March 1, 2027, 25% on March 1, 2028, and 50% on March 1, 2029.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion.

The restricted stock units vest 25% on March 1, 2027, 25% on March 1, 2028, and 50% on March 1, 2029.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion.

The restricted stock units vest 25% on March 1, 2027, 25% on March 1, 2028, and 50% on March 1, 2029.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Withholding of common stock to satisfy reporting person's tax obligation upon the settlement of vested restricted stock units and performance stock units.

These shares represent the acquisition of common stock resulting from the vesting of earned performance stock units issued under an equity incentive plan of the Company.

These shares represent the acquisition of common stock resulting from the vesting of earned performance stock units issued under an equity incentive plan of the Company.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion.

The restricted stock units vest 25% on March 1, 2027, 25% on March 1, 2028, and 50% on March 1, 2029.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion.

The restricted stock units vest 25% on March 1, 2027, 25% on March 1, 2028, and 50% on March 1, 2029.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

Each restricted stock unit represents a contingent right to receive one share of PRIM common stock or the cash value thereof on the date of settlement, in the Company's discretion. On March 1, 2026, the restricted stock units vested and were settled for an equal number of shares of PRIM common stock.

These shares represent the acquisition of common stock resulting from the vesting of earned performance stock units issued under an equity incentive plan of the Company.

The non-employee director compensation program adopted by the Board in May 2011 and updated July 2024, provides for the issuance of restricted stock with a value of $37,500. The price per share was based on the average closing price during December 2025, resulting in a grant of 294 shares of stock. The shares of stock cannot be sold for a period of twelve months from the date of grant.