As filed with the Securities and Exchange Commission on April 11, 2024 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 20-F ☐REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR ☐ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the fiscal year ended December 31, 2023OR ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934OR☐SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934Date of event requiring this shell company report Commission file number 001–37928 ☐☐☐☐☐☐☐☐☐☐(Exact Name of Registrant as Specified in Its Charter) ChipMOS TECHNOLOGIES INC. (Translation of Registrant’s Name into English) Republic of China (Jurisdiction of Incorporation or Organization) No. 1, R&D Road 1, Hsinchu Science Park Hsinchu 300-092, Taiwan, Republic of China (Address of Principal Executive Offices) Silvia Su Vice President, Finance and Accounting Management Center ChipMOS TECHNOLOGIES INC. No. 1, R&D Road 1, Hsinchu Science Park Hsinchu 300-092, Taiwan, Republic of China Telephone: +886-3-577-0055 Facsimile: +886-3-566-8970 (Name, Telephone, E-mail and/or Facsimile Number and Address of Company Contact Person) Securities registered or to be registered pursuant to Section 12(b) of the Act: Title of Each Class TradingSymbol(s) Name of Each Exchangeon Which Registered Common Shares, par value NT$10 per share*IMOS*The NASDAQ Global Select Market* Securities registered or to be registered pursuant to Section 12(g) of the Act: None (Title of Class) Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act: None (Title of Class) Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report. As of December 31, 2023, 727,240,126 Common Shares, par value NT$10 each, were outstanding. Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☐ If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. Yes ☐ No ☐ Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☐ No ☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☐ No ☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or an emerging growth company. See definition of “large accelerated filer”, “accelerated filer”, and “emerging growth company” in Rule 12b-2 of the Exchange Act. : Large Accelerated Filer☐Accelerated Filer☐Non-Accelerated Filer☐Emerging growth company☐ If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐ If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐ Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing. U.S. GAAP ☐International Financial Reporting Standards as issuedby the International Accounting Standards Board ☐Other ☐ If “O