UCTT · Ultra Clean Holdings, Inc.

Restricted stock units vest over 3 years with equal parts vesting on each anniversary of the vesting commencement date of August 31, 2026.

Represents shares automatically withheld for payment of tax liability arising as a result of the partial settlement of restricted stock unit awards that vested.

The sale reported was effected by the reporting person pursuant to the Rule 10b5-1 trading plan adopted by the reporting person on March 5, 2026.

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $127.5050 to $128.5000. 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 set forth in footnote (3) to this Form 4.

The sale reported was effected by the reporting person pursuant to the Rule 10b5-1 trading plan adopted by the reporting person on March 5, 2026.

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $126.3500 to $127.1650. 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 set forth in footnote (2) to this Form 4.

The sale reported was effected by the reporting person pursuant to the Rule 10b5-1 trading plan adopted by the reporting person on March 5, 2026.

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $129.5900 to $130.2400. 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 set forth in footnote (4) to this Form 4.

Restricted stock units vest over 3 years with equal parts vesting on each anniversary of the vesting commencement date of June 26, 2026.

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $90.8250 to $91.8200. 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 set forth in this footnote (5).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $90.6950 to $91.6450. 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 set forth in this footnote (9).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $91.2400 to $91.8200. 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 set forth in this footnote (11).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.3650 to $89.9950. 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 set forth in this footnote (18).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $90.3450 to $91.2100. 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 set forth in this footnote (15).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $91.6150 to $91.8200. 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 set forth in this footnote (5).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $90.4400 to $91.1800. 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 set forth in this footnote (15).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.2950 to $87.9550. 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 set forth in this footnote (16).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $86.6975 to $87.6400. 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 set forth in this footnote (1).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.2500 to $88.1750. 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 set forth in this footnote (12).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.3650 to $89.8450. 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 set forth in this footnote (13).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.3500 to $90.2300. 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 set forth in this footnote (14).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $91.7500 to $91.9100. 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 set forth in this footnote (10).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.9800 to $90.9000. 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 set forth in this footnote (20).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $88.3400 to $89.1900. 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 set forth in this footnote (3).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.2950 to $87.8200. 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 set forth in this footnote (11).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.2700 to $88.2550. 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 set forth in this footnote (2).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $88.3400 to $89.2125. 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 set forth in this footnote (2).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $91.5350 to $91.8200. 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 set forth in this footnote (16).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.4300 to $90.2150. 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 set forth in this footnote (8).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $85.7600 to $86.5900. 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 set forth in this footnote (11).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $91.5350 to $91.9500. 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 set forth in this footnote (16).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $90.5600 to $91.5350. 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 set forth in this footnote (19).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.6350 to $88.5050. 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 set forth in this footnote (22).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.3600 to $90.2100. 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 set forth in this footnote (3).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.8300 to $90.7900. 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 set forth in this footnote (4).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $86.5900 to $87.5000. 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 set forth in this footnote (17).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $85.5350 to $86.1650. 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 set forth in this footnote (1).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $88.3650 to $89.3000. 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 set forth in this footnote (7).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.1900 to $87.7750. 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 set forth in this footnote (6).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.0900 to $89.6400. 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 set forth in this footnote (9).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $88.3700 to $89.1800. 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 set forth in this footnote (12).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $88.6550 to $89.6050. 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 set forth in this footnote (23).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.5700 to $90.2300. 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 set forth in this footnote (8).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $86.5900 to $87.4800. 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 set forth in this footnote (21).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.8000 to $88.7900. 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 set forth in this footnote (2).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $91.7500 to $91.8200. 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 set forth in this footnote (10).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $87.9900 to $88.9750. 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 set forth in this footnote (8).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $90.6600 to $91.6300. 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 set forth in this footnote (25).

This is the weighted average sale price. Shares were sold in multiple transactions at prices from $89.6550 to $90.2150. 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 set forth in this footnote (24).