Ultra Clean Holdings, Inc.

14. REPORTABLE SEGMENTS

The Company’s Chief Executive Officer is the Company’s chief operating decision maker (CODM). The CODM primarily uses income from operations to evaluate each segment’s performance and allocate resources, primarily through periodic budgeting and segment performance reviews. Significant expenses within segment operating profit include cost of revenue,

• 21 - research and development, and selling, general and administrative expenses, which are each separately presented on the Company’s Condensed Consolidated Statements of Operations.

The Company’s reportable segments are determined based on the nature of their revenue streams and the Company’s internal organization structure.

The Company prepared financial results based ontwo operating segments (Products and Services) andtwo reportable segments (Products and Services).

The following table describes each segment:

The CODM uses segment operating profit or loss to evaluate performance and to allocate capital resources. Segment operating profit or loss is defined as a segment’s income or loss from continuing operations before interest and other income (expense), net and provision for income taxes. Any intercompany sales and associated profit (and any other intercompany items) are eliminated from segment results.

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Segment Data

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Long-lived assets comprised of operating lease right-of-use assets and property, plant and equipment, net, are reported based on the location of the asset. The carrying amount of long-lived assets in United States, Malaysia, Israel, South Korea and other foreign countries were $174.3 million, $81.8 million, $71.5 million, $51.9 million and $106.5 million, respectively as of September 26, 2025, and $176.9 million, $83.2 million, $75.2 million, $49.8 million and $101.8 million, respectively as of December 27, 2024.