CALIX, INC.

Item 2.02 Results of Operations and Financial Condition. On July 20, 2026, Calix, Inc. (the “Company”) issued a press release announcing it has publicly disseminated a stockholder letter with its financial results for the second quarter ended June 27, 2026. The press release is attached hereto as Exhibit 99.1. The stockholder letter, a copy of which is attached hereto as Exhibit 99.2 and incorporated herein by reference, includes reference to the non-GAAP measures of non-GAAP gross margin, non-GAAP operating expenses, non-GAAP sales and marketing investments, non-GAAP research and development investments, non-GAAP general and administrative investments, non-GAAP effective income tax rate, non-GAAP net income or profitability, non-GAAP net income per diluted common share and non-GAAP free cash flow. These non-GAAP measures are provided to enhance the reader’s understanding of the Company’s operating performance as they exclude non-cash stock-based compensation and intangible asset amortization and the impact from changes in income taxes, which the Company believes are not indicative of its core operating results. Management believes that the non-GAAP measures used in this stockholder letter provide investors with important perspectives into the Company’s ongoing business performance and management uses these non-GAAP measures to evaluate financial results and to establish operational goals. The presentation of these non-GAAP measures is not meant to be a substitute for results presented in accordance with U.S. GAAP, but rather should be evaluated in conjunction with those GAAP results. A reconciliation of the non-GAAP results to the most directly comparable U.S. GAAP results is contained in tabular form in Exhibit 99.2. The non-GAAP financial measures used by the Company may be calculated differently from, and therefore may not be comparable to, similarly titled measures used by other companies. Such information shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and is not incorporated by reference into any filing of the Company, whether made before or after the date hereof, regardless of any general incorporation language in such filing.