May 10, 2016

TRADING SYMBOLS - United States (NYSE MKT): HTM

U.S. GEOTHERMAL INC. REPORTS FIRST QUARTER 2016 RESULTS

AND REAFFIRMS 2016 GUIDANCE

Highlights

<!--[if !supportLists]--> �       <!--[endif]--> Fourteenth straight quarter of positive EBITDA and Cash Flow From Operations

<!--[if !supportLists]--> �       <!--[endif]--> Increased revenue and cash flow from operations versus previous year

<!--[if !supportLists]--> �       <!--[endif]--> Completed payment for the majority interest in Raft River project

<!--[if !supportLists]--> �       <!--[endif]--> Completed payment for the 3 new power plant units acquired at 5% of original cost

<!--[if !supportLists]--> �       <!--[endif]--> Signed transmission Interconnection Agreement for 30 MW WGP Geysers project in California

BOISE, IDAHO May 10, 2016 � U.S. Geothermal Inc. (the �Company�) (NYSE MKT: HTM), a leading and profitable renewable energy company focused on the development, production, and sale of electricity from geothermal energy, announced today its financial and operating results for the first three months ending March 31, 2016 (the �First Three Months� or �First Quarter�), reaffirmed guidance for 2016, and highlighted notable achievements for the First Quarter.  This earnings release should be read in conjunction with US Geothermal�s financial statements, and management�s discussion and analysis (�MD&A�), which are available on the Company�s website at www.usgeothermal.com and have been posted at the U.S. Securities and Exchange Commission website at www.sec.gov  and on SEDAR at www.sedar.com.

Summary of First Quarter 2016 Financial Results:                                     Three Months Ended March 31

(in millions, except per share amounts)

* Refer to Appendix for further detail on EBITDA, Adjusted EBITDA, and Net Income, As Adjusted.

Operating Revenue for the First Quarter was $8.50 million, compared to $8.47 million for the prior year period. Adjusted EBITDA for the First Quarter was $4.84 million, compared to $5.13 million for the prior year period, while EBITDA was $3.79 million for the First Quarter compared to $4.72 million for the prior year.  Net Income (as adjusted) for the First Quarter was $2.03 million, compared to $2.20 million in the prior year period. Net Income for the First Quarter was $1.19 million, compared to $1.76 million in the prior year period.  Net Income attributable to US Geothermal (as adjusted) for the First Quarter was $0.99 million, or $0.01 per share, compared to $1.17 million, or $0.01 per share in the prior year period.  Net Income attributable to US Geothermal for the First Quarter was $0.15 million, or $0.00 per share, compared to $0.73 million, or $0.01 per share in the prior year period, driven largely by a one-time non-recurring First Quarter expense of $0.75 million associated with financial advisory services and their related costs.

�Our first quarter demonstrated steady and reliable performance from our operating assets� said Dennis Gilles, Chief Executive Officer. �However our results were negatively impacted by onetime expenses associated with financial advisory services.�  

Full Year 2016 Guidance (Consolidated)*:

Full Year 2016 Guidance (Attributable to US Geothermal)*:

* Guidance figures represent Current Operating Power Plants only.   Refer to Appendix for further detail of EBITDA, Adjusted EBITDA, and Net Income, As Adjusted.

Development Projects Update

<!--[if !supportLists]--> �        <!--[endif]--> Received signed Large Generator Interconnection Agreement from the California Independent System Operator and Pacific Gas & Electric for the 30 MW WGP Geysers project in California.  The Company continues to seek a Power Purchase Agreement (�PPA�) prior to starting plant construction.

<!--[if !supportLists]--> �        <!--[endif]--> Engaged independent reservoir engineering firm from Iceland to review drilling data, provide recommendations for additional drilling, and provide resource estimate in preparation for Guatemalan request for proposal for geothermal PPAs expected in Q2 of this year.

<!--[if !supportLists]--> �        <!--[endif]--> Finalized the acquisition of three unconstructed binary power plants, at a small fraction of their original cost, providing flexibility to install these plants at new projects with significantly lower project capital costs, and accelerate development timelines.

<!--[if !supportLists]--> �        <!--[endif]--> Obtaining approval to drill additional water supply wells at Neal Hot Springs, Oregon in support of hybrid cooling project which could add approximately 3+ MW to the project annual average generation.

<!--[if !supportLists]--> �        <!--[endif]--> Preparing for drilling second production leg on well RRG-2 at Raft River which could add up to 3 MW to the project generation. Drilling scheduled for Q2 of this year.

NOTABLE HIGHLIGHTS AND ACHIEVEMENTS FOR FIRST QUARTER 2016 INCLUDE

� Operations:

<!--[if !supportLists]--> -       <!--[endif]--> Achieved average availabilities for the First Quarter for each plant (excluding planned maintenance hours) as follows: Neal Hot Springs � 96.7%, San Emidio � 99.4%, Raft River � 100.0%.

<!--[if !supportLists]--> -       <!--[endif]--> Generated fleet wide total 93,788 megawatt-hours for the period, as compared to 95,926 megawatt-hours in the prior year.

<!--[if !supportLists]--> -       <!--[endif]--> Increased cash flow from operations to slightly over $5 million.

� Strategic:

<!--[if !supportLists]--> -       <!--[endif]--> Concluded engagement of Marathon Capital�s investigation of strategic alternatives with the Board of Directors determining that continuing to execute the Company�s strategic growth plan is the best path to maximizing long term stockholder value.

<!--[if !supportLists]--> -       <!--[endif]--> Paid Goldman Sachs the final installment of $1,635,000 for the purchase of their majority interest in the Raft River project.

<!--[if !supportLists]--> -       <!--[endif]--> Paid Leidos the final payment of $750,000 for the three new unconstructed power plants.

<!--[if !supportLists]--> -       <!--[endif]--> Signed Transmission Interconnection Agreement with CAISO and PG&E for Geysers Power Plant.

� Cash Management:

<!--[if !supportLists]--> -       <!--[endif]--> Ended the First Quarter with $224.7 million in Total Assets, Cash and Cash Equivalents of $7.4 million, and Restricted Cash of $22.3 million.

<!--[if !supportLists]--> -       <!--[endif]--> Reduced long-term debt by $1.8 million to $92.5 million ($67.7 million - net of partnership interests).

Conference Call

U.S. Geothermal Inc. will host a telephone conference call for investors and analysts on Wednesday, May 11^th, 2016 at 1:00 p.m. ET (10:00 a.m. PT) to discuss their First Quarter 2016 results, which were filed after the Market Close on Tuesday May 10^th, 2016.

The conference call may be accessed by dialing (877) 407-8133 in the United States and Canada, or (201) 689-8040 internationally.  A simultaneous webcast of the conference call will be provided through:  http://www.investorcalendar.com/IC/CEPage.asp?ID=174993
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Please visit our Website at: http://www.usgeothermal.com

About U.S. Geothermal Inc.:

U.S. Geothermal Inc. is a leading and profitable renewable energy company focused on the development, production and sale of electricity from geothermal energy. The company is currently operating geothermal power projects Neal Hot Springs, Oregon, San Emidio, Nevada and Raft River, Idaho for a total power generation of approximately 45 MWs. The company is also developing an additional 90 MW�s of projects at: the Geysers, California; a second phase project at San Emidio, Nevada; at Crescent Valley, Nevada; and the El Ceibillo project located near Guatemala City, Guatemala.  US Geothermal�s growth strategy is to reach 200 MWs of generation by 2020 through a combination of internal development and strategic acquisitions.

FOR ADDITIONAL INFORMATION PLEASE CONTACT:

Saf Dhillon - Investor Relations
U.S. Geothermal Inc.
Tel: 866-687-7059
Fax: 208-424-1030
saf@usgeothermal.com

The information provided in this news release may contain forward-looking statements within the definition of the Safe Harbor provisions of the US Private Securities Litigation Reform Act of 1995.  Readers are cautioned to review the risk factors identified by the company in its filings with US and Canadian securities agencies. All statements, other than statements of historical fact, included herein, without limitation, statements relating to the future operating or financial performance of U.S. Geothermal, are forward-looking statements. Forward-looking statements are frequently, but not always, identified by words such as "expects", "anticipates", "believes", "intends", "estimates", "potential", "possible", and similar expressions, or statements that events, conditions, or results "will", "may", "could", or "should" occur or be achieved. These forward-looking statements may include statements regarding perceived merit of properties; interpretation of the results of well tests; project development; resource megawatt capacity; capital expenditures; timelines; strategic plans; or other statements that are not statements of fact. Forward-looking statements involve various risks and uncertainties. There can be no assurance that such statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such statements. Important factors that could cause actual results to differ materially from U.S. Geothermal's expectations include the uncertainties involving the availability of financing in the debt and capital markets; uncertainties involved in the interpretation of results of well tests; the need for cooperation of government agencies in the development and operation of properties; the need to obtain permits and governmental approvals; risks of construction; unexpected cost increases, which could include significant increases in estimated capital and operating costs; and other risks and uncertainties disclosed in U.S. Geothermal's Annual Report on Form 10-K for the year ended December 31, 2015 filed with the United States Securities and Exchange Commission and Canadian securities regulatory authorities and in other U.S. Geothermal reports and documents filed with applicable securities regulatory authorities from time to time. Forward-looking statements are based on management�s expectations, beliefs and opinions on the date the statements are made.  U.S. Geothermal Inc. assumes no obligation to update forward-looking statements if management�s expectations, beliefs, or opinions, or other factors, should change.

The NYSE MKT does not accept responsibility for the adequacy of this release.

APPENDIX

The below table summarizes revenues for 2016 and 2015, and reflects seasonality by quarter of our generation and corresponding revenues.

RECONCILIATION OF TERMS:

The following tables provide a reconciliation of the EBITDA, EBITDA Adjusted, and Net Income Adjusted; presented for both the Consolidated financials as well as Attributable to US Geothermal only (consolidated less minority interest).

EBITDA is calculated as net income before interest, income taxes, depreciation and amortization, and is not a measurement of financial performance or liquidity under generally accepted accounting principles in the United States.  EBITDA is presented as a metric commonly used by securities analysts, investors and other interested parties in the evaluation of a company�s ability to service and/or incur debt.

Adjusted EBITDA reflects EBITDA adjusted to exclude discretionary exploration costs, non-cash stock compensation as well as the value assigned to stock options granted, and write-off of discontinued exploration activities and other large non-recurring items. 

Net Income, As Adjusted reflects Net Income before Tax and other large non-recurring items and is provided to support year over comparisons.  The Company recognized a Deferred Tax Asset starting in 2015, and though tax amounts are now reflected in our Financials as required by GAAP, any current tax obligation is offset by a reduction in the recognized Deferred Tax Asset.

CONSOLIDATED:

First Quarter Financial Results (Consolidated):                                                  Three Months Ended March 31

Net Income, As Adjusted (Consolidated):                                                           Three Months Ended March 31

ATTRIBUTABLE TO US GEOTHERMAL (Consolidated less Minority Interests):

First Quarter Financial Results (Attributable to US Geothermal):                  Three Months Ended March 31

Net Income, Attributable to US Geothermal, As Adjusted                             Three Months Ended March 31

For 2016 Net Income, As Adjusted, and Net Income Attributable to US Geothermal, As Adjusted, along with Adjusted EBITDA and Adjusted EBITDA, Attributable to US Geothermal were impacted by a one-time non-recurring expense of:

<!--[if !supportLists]--> �        <!--[endif]--> Non-recurring  - Financial Advisory and related costs of $0.75 million