UNITED STATES SECURITIES AND EXCHANGE COMMISSION

1 UNITED STATESSECURITIES AND EXCHANGE COMMISSIONW ashington, 20549 FORM 10-K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended december 31, 2020OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to COMMISSION file number 001-14905 BERKSHIRE HATHAWAY INC.(Exact name of Registrant as specified in its charter)Delaware47-0813844 State or other jurisdiction ofincorporation or organization( EmployerIdentification No.)

2 3555 Farnam Street, Omaha, Nebraska68131(Address of principal executive office)(Zip Code)Registrant s telephone number, including area code (402) 346-1400 SECURITIES registered pursuant to Section 12(b) of the Act: Title of each classTrading SymbolsName of each EXCHANGE on which registeredClass A Common StockClass B Common Senior Notes due Senior Notes due Senior Notes due Senior Notes due Senior Notes due Senior Notes due Senior Notes due Senior Notes due Senior Notes due Senior Notes due York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock ExchangeNew York Stock

3 ExchangeNew York Stock ExchangeSecurities registered pursuant to Section 12(g) of the Act: NONEI ndicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the SECURITIES Act. Yes No Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. 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.

4 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 ( 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, a smaller reporting company, or an emerging growth company. See the definitions of large accelerated filer, accelerated filer, smaller reporting company, and emerging growth company in Rule 12b-2 of the EXCHANGE Act.

5 Large accelerated filer Accelerated filer Non-accelerated filer Smaller reporting company Emerging growth company If an emerging growth company, 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 7262(b)) by the registered public accounting firm that prepared or issued its audit report.

6 Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes No State the aggregate market value of the voting stock held by non-affiliates of the Registrant as of June 30, 2020: $336,500,000,000* Indicate the number of shares outstanding of each of the Registrant s classes of common stock: February 16, 2021 Class A common stock, $5 par value640,586 sharesFebruary 16, 2021 Class B common stock, $ par value 1,336,348,609 sharesDOCUMENTS INCORPORATED BY REFERENCEP ortions of the Proxy Statement for the Registrant s Annual Meeting to be held May 1, 2021 are incorporated in Part III.

7 * This aggregate value is computed at the last sale price of the common stock as reported on the New York Stock EXCHANGE on June 30, 2020. It does not include the value of Class A common stock and Class B common stock held by Directors and Executive Officers of the Registrant and members of their immediate families, some of whom may not constitute affiliates for purpose of the SECURITIES EXCHANGE Act of 1934. Table of Contents Page I Item DescriptionK-1 Item FactorsK-22 Item Staff CommentsK-26 Item of PropertiesK-26 Item ProceedingsK-28 Item Safety DisclosuresK-29 Part IIItem for Registrant s Common Equity, Related Security Holder Matters and IssuerPurchases of Equity SecuritiesK-29 Item Financial DataK-32 Item s Discussion and Analysis of Financial Condition and Results of OperationsK-33 Item and Qualitative Disclosures About Market RiskK-66 Item Statements and Supplementary DataK-67 Consolidated Balance Sheets december 31.

8 2020 and december 31, 2019K-70 Consolidated Statements of Earnings Years ended december 31, 2020, december 31, 2019, and december 31, 2018K-72 Consolidated Statements of Comprehensive Income Years ended december 31, 2020, december 31, 2019, and december 31, 2018K-73 Consolidated Statements of Changes in Shareholders Equity Years ended december 31, 2020, december 31, 2019, and december 31, 2018K-73 Consolidated Statements of Cash Flows Years ended december 31, 2020, december 31, 2019, and december 31, 2018K-74 Notes to Consolidated Financial StatementsK-75 Item in and Disagreements with Accountants on Accounting and Financial DisclosureK-116 Item and ProceduresK-116 Item InformationK-116 Part IIIItem.

9 Executive Officers and Corporate GovernanceK-116 Item CompensationK-116 Item Ownership of Certain Beneficial Owners and Management and Related StockholderMattersK-116 Item Relationships and Related Transactions and Director IndependenceK-116 Item Accountant Fees and ServicesK-116 Part IVItem and Financial Statement SchedulesK-116 Exhibit IndexK-120 SignaturesK-122 K-1 Part IItem 1. Business Description Berkshire Hathaway Inc. ( Berkshire, Company or Registrant ) is a holding company owning subsidiaries engaged in a large number of diverse business activities.

10 The most important of these are insurance businesses conducted on both a primary basis and a reinsurance basis, a freight rail transportation business and a group of utility and energy generation and distribution businesses. Berkshire also owns and operates numerous other businesses engaged in a variety of activities, as identified herein. Berkshire is domiciled in the state of Delaware, and its corporate headquarters is in Omaha, Nebraska. Berkshire s operating businesses are managed on an unusually decentralized basis. There are few centralized or integrated business functions.