美国能源美股招股说明书(2026-03-09版)

U.S. Energy Corp. 8,800,000 Shares of Common Stock U.S. Energy Corp. (“U.S. Energy,” the “Company,” “we,” “our” or “us”) is offering 8,800,000shares of its commonstock, $0.01 par value per share (“Common Stock”), pursuant to this prospectus supplement and the accompanying baseprospectus. We are offering all of the shares of Common Stock offered by this prospectus on a firm commitment underwrittenbasis. Our Common Stock is listed on the Nasdaq Capital Market under the symbol “USEG.” On March 6, 2026, the lastreported sale price for our Common Stock on the Nasdaq Capital Market was $1.15per share. As of March 6, 2026, the aggregate market value of our outstanding Common Stock held by non-affiliates wasapproximately $34.9 million, which was calculated based on 30,373,375 shares of outstanding Common Stock held by non-affiliates, at a price per share of $1.15, the closing price of our Common Stock on March 6, 2026, the highest closing price of theCompany’s Common Stock on the Nasdaq Capital Market during the preceding sixty (60) day trading period. Pursuant toGeneral Instruction I.B.6 of Form S-3, in no event will we sell the securities described in this prospectus in a public primaryoffering with a value exceeding more than one-third (1/3) of the aggregate market value of our Common Stock held by non-affiliates in any twelve (12)-month period, so long as the aggregate market value of our outstanding Common Stock held by non-affiliates remains below $75,000,000. During the twelve (12) calendar months prior to and including the date of this prospectussupplement, we have not offered or sold any securities pursuant to General Instruction I.B.6 of Form S-3. Investing in our securities involves a high degree of risk. Before making an investment decision, please read theinformation in the section titled“Risk Factors”beginning on pageS-7of this prospectus supplement and in the documentsincorporated by reference into this prospectus supplement and the accompanying base prospectus. We have agreed to pay the underwriter underwriting discounts and commissions equal to 5.75% of the aggregategross proceeds in this offering from the sale of the shares of Common Stock. See “Underwriting”beginning on pageS-14 for additional information regarding the compensation payable to the underwriter. Neither the U.S.Securities and Exchange Commission nor any state securities commission has approved ordisapprovedof these securities or passed upon the adequacy or accuracy of this prospectus supplement or theaccompanying base prospectus. Any representation to the contrary is a criminal offense. Delivery of the securities offered hereby is expected to be made on or about March 10, 2026, subject to the satisfaction ofcertain closing conditions. Roth Capital Partners The date of this prospectus supplement is March 9, 2026. Table of Contents TABLE OF CONTENTS Prospectus Supplement ABOUT THIS PROSPECTUS SUPPLEMENTCAUTIONARY STATEMENT CONCERNING FORWARD LOOKING STATEMENTSPROSPECTUS SUPPLEMENT SUMMARYTHE OFFERINGRISK FACTORSUSE OF PROCEEDSDIVIDEND POLICYCAPITALIZATIONDILUTIONDESCRIPTION OF SECURITIES WE ARE OFFERINGUNDERWRITINGLEGAL MATTERSEXPERTSINTERESTS OF NAMED EXPERTS AND COUNSELWHERE YOU CAN FIND MORE INFORMATIONINCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE Prospectus ABOUT THIS PROSPECTUSINCORPORATION OF CERTAIN DOCUMENTS BY REFERENCEPROSPECTUS SUMMARYSECURITIES REGISTERED HEREBY THAT WE MAY OFFERRISK FACTORSFORWARD-LOOKING STATEMENTSUSE OF PROCEEDSDESCRIPTION OF COMMON STOCKDESCRIPTION OF PREFERRED STOCKDESCRIPTION OF DEBT SECURITIESDESCRIPTION OF WARRANTSDESCRIPTION OF UNITSLEGAL OWNERSHIP OF SECURITIESPLAN OF DISTRIBUTIONPROSPECTUS SUPPLEMENTSLEGAL MATTERSEXPERTSWHERE YOU CAN FIND MORE INFORMATION ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement and the accompanying base prospectus are part of a registration statement onFormS-3(FileNo.333-290232)that we filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registrationprocess. This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of thisoffering and also adds to and updates information contained in the accompanying base prospectus and the documents incorporatedby reference herein. The second part, the accompanying base prospectus, provides more general information. Generally, when werefer to this prospectus, we are referring to both parts of this document combined. To the extent there is a conflict between theinformation contained in this prospectus supplement and the information contained in the accompanying base prospectus or anydocument incorporated by reference therein filed prior to the date of this prospectus supplement, you should rely on theinformation in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with astatement in another document having a later date—for example, a document incorporated by reference in the