As filed with the Securities and Exchange Commission on October 31, 2012November 15, 2021

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933
logoworkivaa.jpg

LOGO

NATURAL GAS SERVICES GROUP, INC.

*

(Exact name of registrant as specified in its charter)

Colorado 
Colorado75-2811855

(State or other jurisdiction of

incorporation or organization)

(I.R.S. employer

identification no.)

508 West Wall Street,

404 Veterans Airpark Lane, Suite 550

300

Midland, Texas 79701

79705

(432) 262-2700

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Stephen C. Taylor, Chief Executive Officer

508 West Wall Street,

404 Veterans Airpark Lane, Suite 550

300

Midland, Texas 79701

79705

(432) 262-2700

(Name, address, including zip code, and telephone number, including area code, of agent for service)

The Commission is requested to send copies of all communications to:

David A. Thayer, Esq.

Jones & Keller, P.C.

19991675 Broadway, Suite 315026

th Floor

Denver, CO 80202

Telephone: (303) 573-1600

Facsimile: (303) 573-0769573-8133





Approximate date of commencement of proposed sale to the public:public: from time to time after this registration statement becomes effective as determined by market conditions and other factors.

effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.   ¨

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.   x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act of 1933, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.   ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.   ¨

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.   ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer
 ¨
Accelerated filer 
 Accelerated
Non-accelerated filer
 x
Smaller reporting company
Non-accelerated filer 
¨
  (Do
(Do not check if a smaller reporting company)Smaller reporting company¨


Calculation of Registration Fee

Title of Securities (1)

  Aggregate
offering price
(2)
   Amount of
registration
fee (3)
 

Common Stock

   --     --  

Preferred Stock

   --     --  

Depositary Shares

   --     --  

Debt Securities

   --     --  

Rights

   --     --  

Units

   --     --  

Warrants

   --     --  

Total

  $150,000,000    $20,460  
Title of Securities (1)
 (1)
Aggregate offering price (2)
Any securities registered hereunder may be sold separately or as units with other securities registered hereunder. The securities which may be offered pursuant to this Registration Statement include, pursuant to Rule 416 of the Securities Act of 1933, as amended (the “Securities Act”), such additional number of shares of the registrant’s common stock that may become issuable as a result of any stock split, stock dividends or similar event. In the event the registrant elects to offer to the public fractional interests in its shares of preferred stock registered hereunder, depositary shares, evidenced by depository receipts issued pursuant to a deposit agreement, will be distributed to those persons purchasing fractional interests and the shares of preferred stock will be issued to the depository under any such agreement.


 (2)An indeterminate aggregate offering price and number or amount
Amount of the securities of each identified class is being registered as may from time to time be sold at indeterminate prices, with a maximum aggregate offering price not to exceed $150,000,000. Separate consideration may or may not be received for securities that are issuable upon conversion of, or in exchange for, or upon exercise of, convertible or exchangeable securities. The proposed maximum aggregate offering price for each class of securities to be registered is not specified pursuant to General Instruction II.D of Form S-3.registration fee (3)

Common Stock (3)--All--
Preferred Stock----
Depositary Shares----
Debt Securities----
Rights----
Units----
Warrants----
Guarantee of the $150,000,000 of securities registered pursuant to this registration statement (collectively, the “Unsold Securities”) consist of unsold securities previously registered by the Registrant on its Registration Statement on Form S-3 filed on August 14, 2009 and declared effective on November 24, 2009 (File No. 333-161346) (the “Prior Registration Statement”). As of the date hereof, all of the UnsoldDebt Securities remain unsold. Pursuant to Rule 415(a)(6) under the Securities Act of 1933, the $8,370 registration fee previously paid by the Registrant in connection with the Unsold Securities will be used to offset the current fee of $20,460. As a result, an additional filing fee of $12,090 is being paid herewith. In accordance with applicable rules of the Securities and Exchange Commission, the Registrant may continue to offer and sell the Unsold Securities during the grace period afforded by Rule 415(a)(4)
----
 Total$150,000,000
$13,905 (5) under the Securities Act of 1933, and, if the Registrant sells any of the Unsold Securities during that grace period, then the Registrant will identify in a pre-effective amendment to this registration statement the new amount of the Unsold Securities to be carried forward to this registration statement. Pursuant to Rule 415(a)(6) under the Securities Act of 1933, the offering of the Unsold Securities registered under the Prior Registration Statement will be deemed terminated as of the date of effectiveness of this registration statement.

(1)Pursuant to Rule 457(o) under the Securities Act of 1933, as amended (the “Securities Act), the securities registered hereunder include such indeterminate (a) number of shares of common stock, (b) number of shares of preferred stock, (c) debt securities, (d) number of depositary shares, (e) warrants to purchase common stock, preferred stock, debt securities or other securities of the Registrant, (f) rights to purchase common stock, preferred stock, debt securities or depositary shares of the Registrant, (g) units, consisting of some or all of



these securities, and (h) guarantees of debt securities, as may be sold from time to time by the Registrant. Any securities registered hereunder may be sold separately or as units with other securities registered hereunder. There are also being registered hereunder an indeterminate number of shares of common stock, preferred stock and debt securities as shall be issuable upon conversion, exchange or exercise of any securities that provide for such issuance. In no event will the aggregate offering price of all types of securities issued by the Registrant pursuant to this registration statement exceed $150,000,000. Pursuant to Rule 416(a), this registration statement also covers any additional securities that may be offered or issued in connection with any stock split, stock dividend or similar transaction.
(2)The proposed maximum per unit and aggregate offering prices per class of securities will be determined from time to time by the Registrant in connection with the issuance by the Registrant of the securities registered under this registration statement and is not specified as to each class of security pursuant to General Instruction II.D of Form S-3 under the Securities Act.
(3)Calculated pursuant to Rule 457(o) under the Securities Act.

(4)Subsidiaries of Natural Gas Services Group, Inc. named as co-registrants may fully and unconditionally guarantee on an unsecured basis the debt securities of Natural Gas Services Group, Inc. In accordance with Rule 457(n), no separate fee is payable with respect to the guarantee of the debt securities being registered.

(5)Pursuant to Rule 415(a)(6), the securities being registered hereunder include $150,000,000 of unsold securities previously registered by the Registrant’s registration statement on Form S-3 (File No. 333-228350-01) (the “Prior Registration Statement”), which was declared effective on December 6, 2018. The filing fee paid in connection with such unsold securities was $18,180 and will continue to apply to the unsold securities registered hereby. To the extent that, after the filing date hereof and prior to the effectiveness of this registration statement, the Registrant sells any such unsold securities pursuant to the Prior Registration Statement, the Registrant will identify in a pre-effective amendment to this registration statement the updated amount of unsold securities from the Prior Registration Statement to be included in this registration statement pursuant to Rule 415(a)(6). Pursuant to Rule 415(a)(6), the offering of the unsold securities under the Prior Registration Statement will be deemed terminated as of the date of effectiveness of this registration statement.

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

*ADDITIONAL SUBSIDIARY GUARANTOR REGISTRANTS

Exact Name of Additional Registrant as Specified in its Charter
State or Other Jurisdiction of
Incorporation or Organization
I.R.S. Employer Identification No.
NGSG Properties, LLC(1)
ColoradoN/A
(1)Address, including zip code, and telephone number, including area code, for the subsidiary is:

404 Veterans Airpark Lane, Suite 300
Midland, Texas 79705
(432) 262-2700










The information in this preliminary prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state or jurisdiction where the offer or sale is prohibited.not permitted.

SUBJECT TO COMPLETION, DATED NOVEMBER 15, 2021
Subject to Completion, dated October 31, 2012

PROSPECTUS

$150,000,000

LOGO

logoworkivaa.jpg
Common Stock

Preferred Stock

Depositary Shares

Debt Securities

Rights

Units

Warrants

Guarantees of Debt Securities

We may offer and sell from time to time, underin one or more series or issuances and on terms that we will determine at the time of the offering, any combination of the securities described in this prospectus, up to an indeterminate numberaggregate amount of shares$150,000,000.

We will provide specific terms of our common stock, preferred stock, depositary shares, debt securities, rightsany offering in a supplement to purchase common stock, units consisting of twothis prospectus. Any prospectus supplement may also add, update or more of these classeschange information contained in this prospectus. You should carefully read this prospectus and the applicable prospectus supplement as well as the documents incorporated or series of securities and warrantsdeemed to be incorporated by reference in this prospectus before you purchase any of the other securities thatoffered hereby.

These securities may be offered and sold under this prospectus. We will describe in a prospectus supplement the securities we aresame offering and selling, as well as the specific terms of the securities.

We may offer these securitiesor in amounts, at prices and on terms determined at the time of offering. We may sell the securities directlyseparate offerings; to you, through agents we select, or through underwriters, dealers and agents; or directly to purchasers. The names of any underwriters, dealers we select. If we useor agents underwriters or dealers to sellinvolved in the sale of our securities, we will name them and describe their compensation and any over-allotment options held by them will be described in athe applicable prospectus supplement.

See the section titled “Plan of Distribution.”


Our common stock is quoted on The New York Stock Exchange under the symbol “NGS.” On October 26, 2012,November 8, 2021, the last reported sale price of our common stock was $15.46$12.64 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing on the NYSE or any other securities exchange of the securities covered by the prospectus supplement.





We may amend or supplement this prospectus from time to time by filing amendments or supplements as required. You should read this entire prospectus and any amendments or supplements carefully before you make your investment decision.



Investing in our securities involves certain risks. You should carefully consider the matters set forth in “Risk Factors” on page 56 of this prospectus and in the applicable prospectus supplement, along with any risk factor information incorporated by reference herein for certain risks you should consider. You should read the entire prospectus carefully before you make your investment decision.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is, 2012. November 15, 2021
































TABLE OF CONTENTS


FORWARD-LOOKING STATEMENTS

.........................................................................................................

ABOUT THIS PROSPECTUS

..........................................................................................................................
1

INFORMATION ABOUT NATURAL GAS SERVICES GROUP, INC.INC

. .......................................................

RISK FACTORS

...............................................................................................................................................
5
SECURITIES WE MAY OFFER ......................................................................................................................

DESCRIPTION OF COMMON STOCK AND PREFERRED STOCK

..........................................................
6
DESCRIPTION OF DEBT SECURITIES AND GUARANTEES ...................................................................

DESCRIPTION OF DEPOSITARY SHARES

.................................................................................................
10

DESCRIPTION OF DEBT SECURITIESWARRANTS

....................................................................................................................
14

DESCRIPTION OF RIGHTS

............................................................................................................................
25

DESCRIPTION OF UNITS

...............................................................................................................................
26

DESCRIPTION OF WARRANTS

26

USE OF PROCEEDS

.........................................................................................................................................
26

RATIO OF EARNINGS TO FIXED CHARGES

27

PLAN OF DISTRIBUTION

..............................................................................................................................
27

LEGAL MATTERS

...........................................................................................................................................
29

EXPERTS

...........................................................................................................................................................
29

TRANSFER AGENT AND REGISTRAR

........................................................................................................
30
WHERE YOU CAN FIND MORE INFORMATION .......................................................................................

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

.......................................................
30

31



You should rely on the information contained in this prospectus. We have not authorized anyone to provide you with information different from that contained in this prospectus. Offers to sell the securities will be made only in jurisdictions where offers and sales are permitted. The information contained in this prospectus is accurate only as of the date of this prospectus, regardless of the time of delivery of this prospectus or of any sale of the securities.

-i-









FORWARD-LOOKING STATEMENTS

Certain statements contained in this prospectus are not statements of historical fact and constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act (the “Act”), including, without limitation, the statements specifically identified as forward-looking statements within this prospectus. Many of these statements contain risk factors as well. In addition, certain statements in future filings by the Company with the Securities and Exchange Commission ("SEC"), in press releases, and in oral and written statements made by or with the approval of the Company which are not statements of historical fact constitute forward-looking statements within the meaning of the Act. Examples of forward-looking statements, include, but are not limited to: (i) projections
•    conditions in the oil and natural gas industry, including the supply and demand for oil and natural gas and wide fluctuations and possible prolonged depression in the prices of revenues, income or loss, earnings or loss per share,oil and natural gas;
•    economic challenges presently faced by our customers in the payment or non-payment of dividends, capital structure,oil and other financial items, (ii) statementsnatural gas business that, in turn, could adversely affect our sales, rentals and collectability of our plansaccounts receivable;
•    regulation or prohibition of new well completion techniques;
•    competition among the various providers of compression services and objectives by our managementproducts;
•    changes in safety, health and environmental regulations;
•    changes in economic or Board of Directors including those relating to planned developmentpolitical conditions in the markets in which we operate;
•    failure of our natural gas compression business, (iii) statementscustomers to continue to rent equipment after expiration of future economic performancethe primary rental term;

•    our ability to retain key members of senior management and (iv) statements of assumptions underlying such statements. Wordskey technical and financial employees;
•    the inherent risks associated with our operations, such as “believes,” “anticipates,” “expects,” “intends,” “targeted,” “may,” “will”equipment defects, malfunctions and similar expressionsnatural disasters;
•    our inability to comply with covenants in our debt agreements and the decreased financial flexibility associated with our debt;

risks in connection with potential acquisitions and the integration of significant acquisitions or assets acquired through a merger or otherwise;
•    the possibility that acquisitions and divestitures may involve unexpected costs or delays, and those acquisitions may not achieve intended benefits;
-1-


•    the possibility that potential divestitures may not occur or could be burdened with unforeseen costs;
•    unanticipated reductions in the borrowing base under the credit agreement we are intended to identify forward-looking statements but are notparty to;
•    future capital requirements and availability of financing;
•    fabrication and manufacturing costs;
•    general economic conditions, whether internationally, nationally or in the exclusive meansregional and local market areas in which we conduct business, may be less favorable than expected, including the possibility that economic conditions in the United States will worsen and that capital markets for equity and debt will be disrupted or unavailable;
•    acts of identifying such statements.

terrorism; and

•    fluctuations in interest rates.

Such forward-looking statements speak only as of the date on which such statements are made, and the Company undertakes no obligation to update any forward-looking statement to reflect events or circumstances after the date on which such statement is made to reflect the occurrence of unanticipated events.



ABOUT THIS PROSPECTUS

This is only a summary and does not contain all of the information that you should consider before investing in our common stock. You should read the entire prospectus carefully, including the “Risk Factors” section as well as the information incorporated by reference into this prospectus under “Incorporation of Certain Information by Reference—Reference - Where You Can Find More Information.”


In this prospectus, the terms “company,” “we,” “us,” and “our” refer to Natural Gas Services Group, Inc., a Colorado corporation.

-1-



This prospectus is part of a registration statement that we filed with the Securities and Exchange CommissionSEC utilizing a shelf registration process. Under the shelf registration process, we may offer shares of our common stock, preferred stock, depositary shares, various series of debt securities, rights, units and warrants to purchase any of such securities with a total value of up to $150,000,000 from time to time under this prospectus at prices and on terms to be determined by market conditions at the time of offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

-2-


designation or classification;

aggregate principal amount or aggregate offering price;

maturity;

original issue discount, if any;

rates and times of payment of interest, dividends or other payments, if any;

redemption, conversion, exchange, settlement or sinking fund terms, if any;

conversion, exchange or settlement prices or rates, if any, and, if applicable, any provisions for changes to or adjustments in the conversion, exchange or settlement prices or rates and in the securities or other property receivable upon conversion, exchange or settlement;

ranking;

restrictive covenants, if any;

voting or other rights, if any; and

important federal income tax considerations.


A prospectus supplement may include a discussion of risks or other special considerations applicable to us or the offered securities. A prospectus supplement may also add, update or change information in this prospectus. If there is any inconsistency between the information in this prospectus and the applicable prospectus supplement, you must rely on the information in the prospectus supplement. Please carefully read both this prospectus and the applicable prospectus supplement together with additional information described under the heading “Incorporation of Certain Information by Reference—WhereReference--Where You Can Find More Information.” This prospectus may not be used to offer or sell any securities unless accompanied by a prospectus supplement.


The registration statement containing this prospectus, including exhibits to the registration statement, provides additional information about us and the common stock offered under this prospectus. The registration statement can be read at the SEC website or at the SEC’s public reading room mentioned under the heading “Incorporation of Certain Information by Reference—WhereReference--Where You Can Find More Information.”

We have not authorized any underwriter, broker-dealer, salesperson or other person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus and the accompanying supplement to this prospectus. You must not rely upon any information or representation not contained or incorporated by reference in this prospectus or the accompanying prospectus supplement. This prospectus and the accompanying supplement to this prospectus do not constitute an offer to sell or the solicitation of an offer to buy securities, nor do this prospectus and the accompanying supplement to this prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation.  We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change information contained in this prospectus or in any documents that we have incorporated by reference into this prospectus. To the extent there is a conflict between the information contained in this prospectus and the prospectus supplement or any related free writing prospectus, you should rely on the

-2-


information in the prospectus supplement or the related free writing prospectus; provided that if

-3-


any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in this prospectus or any prospectus supplement or any related free writing prospectus — the statement in the document having the later date modifies or supersedes the earlier statement.


We may sell the securities directly to or through underwriters, dealers or agents. We, and our underwriters or agents, reserve the right to accept or reject all or part of any proposed purchase of securities. If we do offer securities through underwriters or agents, we will include in the applicable prospectus supplement:


the names of those underwriters or agents;

applicable fees, discounts and commissions to be paid to them;

details regarding over-allotment options, if any; and

the net proceeds to us.

-3-



INFORMATION ABOUT NATURAL GAS SERVICES GROUP, INC.

We are a leading provider of small, to medium and large horsepower gas compression equipment to the oil and natural gas industry. We focus primarily on the non-conventional oil and natural gas production business in the United States (such as coal bed methane, oil and gas shale and tight gas), which, according to data from the Energy Information Administration (“EIA”), is the single largestoil and fastest growing segment of U.S. gas production.gas). We manufacture, fabricate and rent natural gas compressors that enhance the production of oil and natural gas wells and provide maintenance services for those compressors. In addition, we sell custom fabricated natural gas compressors to meet customer specifications dictated by well pressures, production characteristics and particular applications. We also manufacture and sell flare systems for oil and gas plantprocessing and production facilities.


The vast majority of our rental operations are in non-conventional oil and natural gas regions, which typically have lower initial reservoir pressures and faster well decline rates. These areas usually require gas compression equipment to be installed sooner and with greater frequency. Natural gas compressors are used in a number of applications for the production and enhancement of oil and gas wells and in gas transportation lines and processing plants. Compression equipment is often requiredcan be utilized to boost aan oil and gas well’s productionproductivity to economically viable levels and enable gas to continue to flow in thea pipeline to its destination.

destination or to assist with the production of oil.


We maintain our principal offices at 508 W. Wall St.,404 Veterans Airpark Lane, Suite 550,300, Midland, Texas 7970179705 and our telephone number is (432) 262-2700. Our website address is located athttp://www.ngsgi.com. The information on or that can be accessed through our website is not part of this prospectus. We were incorporated in Colorado on December 17, 1998.

-4-



RISK FACTORS

Any investment in our securities involves risk. You should consider carefully the risk factors described in our periodic reports filed with the SEC (including the risks, uncertainties and assumptions discussed under the heading “Risk Factors” included in our most recent annual report on Form 10-K, as such may be revised or supplemented prior to the completion of this offering by more recently filed quarterly reports on Form 10-Q, each of which is or upon filing
-4-


will be incorporated herein by reference), which may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future, and those identified in any applicable prospectus supplement, as well as other information in this prospectus and any applicable prospectus supplement and the documents incorporated by reference herein before purchasing any of our securities. Each of these risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also impair our business operations.

-5-



SECURITIES WE MAY OFFER

The descriptions of the securities contained in this prospectus, together with the applicable prospectus supplements, summarize all of the material terms and provisions of the various types of securities that we may offer. We will describe in the applicable prospectus supplement relating to any securities the particular terms of the securities offered by that prospectus supplement. We will indicate in the applicable prospectus supplement whether the terms of the securities differ from the terms we have summarized below. We will also include in the prospectus supplement information, where applicable, about material United States federal income tax considerations relating to the securities, and the securities exchange, if any, on which the securities will be listed.

DESCRIPTION OF COMMON STOCK AND PREFERRED STOCK

The following description of our common stock and preferred stock, together with any additional information we include in any applicable prospectus supplement or any related free writing prospectus, summarizes the material terms and provisions of our common stock and the preferred stock that we may offer under this prospectus. While the terms we have summarized below will apply generally to any future common stock or preferred stock that we may offer, we will describe the particular terms of any class or series of these securities in more detail in the applicable prospectus supplement. For the complete terms of our common stock and preferred stock, please refer to our articlesArticles of incorporation and ourIncorporation, as amended and restated bylawsBylaws that are incorporated by reference into the registration statement of which this prospectus is a part or may be incorporated by reference in this prospectus or any applicable prospectus supplement. The terms of these securities may also be affected by the Colorado Business Corporation Act. The summary below and that contained in any applicable prospectus supplement or any related free writing prospectus are qualified in their entirety by reference to our articlesArticles of incorporationIncorporation, as amended and our amended and restated bylaws.

Bylaws.


Common Stock

We are currently authorized to issue 30,000,000 shares of Common Stock, and as of October 1, 2012,November 8, 2021, (i) 12,331,49913,038,719 shares of Common Stock were issued and outstanding, (ii) 750,0001,000,000 shares were reserved for issuance under our 1998 Stock Option Plan, of which 185,586400,503 shares remain unissued; (ii) 300,000and (iii) 500,000 shares were reserved for issuance under the our 2009 Restricted Stock/Unit2019 Equity Incentive Plan, of which 155,84547,135 shares remain unissued and (iii) 45,000 shares were reserved for issuance upon exercise of a Non-Statutory Stock Option Agreement dated August 24, 2005 grantednot subject to one of our executive officers.

outstanding awards.


-5-


Voting Rights

Each share of Common Stock entitles the holder thereof to one vote on each matter for which shareholders are entitled to vote. A majority of the outstanding shares of our Common Stock of the Company entitled to vote at meetings of shareholders, present in person or by proxy, constitute a quorum at any meeting of shareholders. Matters are generally decided by the affirmative vote of a majority of the shares of our Common Stock present in person or by proxy and entitled to vote. TheOur Board of Directors is elected by plurality and cumulative voting is not allowed. Thus, at each election of directors, that number of candidates equaling the number of directors to be elected, having the highest number of votes cast in favor of their election, shall be elected to theour Board of Directors.


Dividends

Holders of Common Stock are entitled to dividends out of funds legally available for such dividends when, if and as declared by the Board of Directors.

-6-


Liquidation

In event of the voluntary or involuntary liquidation, dissolution, distribution of assets or other winding up, holders of our common stock have the right to receive ratably all of the assets remaining after payment of liabilities and liquidation preferences of any preferred stock then outstanding.


Other Matters

Shares of Common Stock are not liable to assessment or further call.  Our Common Stock has no preemptive, conversion or other subscription rights. There are no redemption or sinking fund provisions applicable to our Common Stock. All outstanding shares of Common Stock are validly issued, fully paid and non-assessable.


Preferred Stock

We are authorized to issue 5,000,000 shares of preferred stock, none of which are issued and outstanding as of the date of this prospectus. Our boardBoard of directorsDirectors is authorized to classify or reclassify any unissued portion of our authorized shares of preferred stock to provide for the issuance of shares of other classes or series, including preferred stock in one or more series. We may issue preferred stock from time to time in one or more class or series, with the exact terms of each class or series established by our boardBoard of directors.Directors. Our boardBoard of directorsDirectors may issue preferred stock with voting and other rights that could adversely affect the voting power of the holders of our common stock without seeking shareholder approval. Additionally, the issuance of preferred stock may have the effect of decreasing the market price of the common stock and may adversely affect the voting power of holders of common stock and reduce the likelihood that common shareholders will receive dividend payments and payments upon liquidation.

The rights, preferences, privileges and restrictions of the preferred stock of each series will be fixed by thea certificate of designation relating to each series. We will incorporate by reference into the registration statement of which this prospectus is a part the form of any
-6-


certificate of designation that describes the terms of the series of preferred stock we are offering before the issuance of thesuch related series of preferred stock. The applicable prospectus supplement will specify the terms of the series of preferred stock we are offering, including, but not limited to:

the distinctive designation and the maximum number of shares in the series;

the number of shares we are offering and purchase price per share;

the liquidation preference, if any;

the terms on which dividends, if any, will be paid;

the voting rights, if any, on the shares of the series;

the terms and conditions, if any, on which the shares of the series shall be convertible into, or exchangeable for, shares of any other class or classes of capital stock;

the terms on which the shares may be redeemed, if at all;

any listing of the preferred stock on any securities exchange or market;

-7-


a discussion of any material or special United States federal income tax considerations applicable to the preferred stock; and

any or all other preferences, rights, restrictions, including restrictions on transferability, and qualifications of shares of the series

series.       


The issuance of preferred stock may delay, deter or prevent a change in control.

The prospectus supplement relating to a preferred stock offering will contain a description of the specific terms of that series as fixed by our Board of Directors.

Anti-Takeover Effects of Provisions of our Charter Documents and Colorado Law

The following is a summary of certain provisions of Colorado law, our amended articles of incorporation and bylaws. This summary does not purport to be complete and is qualified in its entirety by reference to the corporate law of Colorado and our amended articles of incorporation and bylaws.

Size of Board. Our Bylaws provide that the size of theour Board of Directors may not be changed except (i) by a resolution adopted by at least 80% of the votes entitled to be cast by each shareholder voting group entitled to vote thereon, or (ii) by unanimous consent of the Board of Directors. This provision of the Bylaws may not be changed except upon approval by at least 80% of the votes entitled to be cast by each voting group entitled to vote thereon.

Filling Vacancies on Board.  Except with respect to a vacancy on the Board of Directors due to the removal of thea Director, any vacancy on the Board may be filled by the affirmative vote of a majority of the shareholders or the Board of Directors. As a result of the ability of the Board to fill a vacancy, such new directors may not be up for shareholder election at the next annual meeting due to the staggered Board classification described below. The overall effect of these provisions may be to prevent a person or entity from immediately acquiring Board control.

Removal of Directors.  Our Bylaws provide that any Director or the entire Board of Directors may be removed for cause only at a special meeting of the shareholders by the affirmative vote of at least 80% of the votes entitled to be cast by each voting group entitled to vote thereon at such meeting, if notice of the intention to act upon such matter shall have been given in the notice calling the meeting. The Bylaws also provide that vacancies arising as a result of the removal of directors by shareholder action may be filled at such meeting by the affirmative
-7-


vote of at least 80% of the shares of the votes entitled to be cast by each voting group entitled to vote thereon. This provision of the Bylaws may not be changed except upon approval by at least 80% of the votes entitled to be cast by each voting group entitled to vote thereon.

Staggered Board of Directors.  Our amended articles of incorporation provide that the Board of Directors is to be divided into three classes, each class to be as nearly equal in number as possible. At each annual meeting of shareholders, members of one of the classes, on a rotating basis, are elected for a three year term. The staggered Board provision cannot be amended or repealed by the directors and cannot be amended or repealed without the affirmative vote of the holders of at least 80% of the votes entitled to be cast in the election of directors.

-8-


Limited Ability for Shareholders to Call a Special Meeting.  Our Bylaws only permit shareholders to call a special meeting if we receive one or more written demands for the meeting, stating the purpose or purposes of the meeting, signed and dated by holders of shares representing at least 10% of all votes entitled to be cast on any issue proposed to be considered at the meeting.

No cumulative voting.  Cumulative voting in the election of directors is not allowed.

Indemnification.  TheOur Articles of Incorporation, as amended, articles provide that our directors and officers shall be indemnified and shall be advanced expenses incurred in defending a civil, criminal, administrative or investigative action, suit or proceeding arising out of their status as directors and officers to the fullest extent allowed by law.

-9-


DESCRIPTION OF DEPOSITARY SHARES

General

We may, at our option, elect to offer fractional shares or multiple shares of preferred

Listing
Our common stock rather than whole individual shares of preferred stock. If we decide to do so, we will issue the preferred stock in the form of depositary shares. Each depository share will represent a fraction or multiple of a share of a particular series of preferred stock and will be evidenced by depositary receipts issued pursuant to the deposit agreement. Depositary receipts will be distributed to those persons purchasing the fractional or multiple shares of preferred stock in accordance with the terms of the prospectus supplement or other offering materials.

The shares of any series of preferred stock represented by depositary shares will be deposited under a deposit agreement between us and a bank or trust company selected by us having its principal office in the United States and having a combined capital and surplus of at least $50,000,000, as preferred stock depositary. Each owner of a depositary share will be entitled to all the rights and preferences of the underlying preferred stock, including dividend, voting, redemption, conversion and liquidation rights, in proportion to the applicable fraction of a share of preferred stock represented by the depositary share.

Dividends and Other Distributions

The preferred stock depositary will distribute all cash dividends or other cash distributions received in respect of the deposited preferred stock to the record holders of depositary shares relating to the underlying preferred stock in proportion to the number of the depositary shares owned by the holders.

The preferred stock depositary will distribute any property received by it other than cash to the record holders of depositary shares entitled to these distributions. If the preferred stock depositary determines that it is not feasible to make a distribution, it may, with our approval, sell the property and distribute the net proceeds from the sale to the holders of the depositary shares.

Conversion or Exchange of Preferred Stock

If a series of preferred stock represented by depositary shares is subject to conversion or exchange, the applicable prospectus supplement will describe the rights or obligations of each record holder of depositary receipts to convert or exchange the depositary shares.

Redemption of Preferred Stock

If we redeem a series of preferred stock represented by depositary shares, the depositary shares will be redeemed from the proceeds received by the preferred stock depositary resulting from the redemption, in whole or in part, of the applicable series of preferred stock. The depositary shares will be redeemed by the preferred stock depositary at a price per depositary share equal to the applicable fraction of the redemption price per share payable in respect of the shares of preferred stock so redeemed.

-10-


Whenever we redeem shares of preferred stock held by the preferred stock depositary, the preferred stock depositary will redeem as of the same date the number of depositary shares representing shares of preferred stock so redeemed. If fewer than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by the preferred stock depositary by lot or ratably or by any other equitable method as the preferred stock depositary decides.

Withdrawal of Preferred Stock

Unless the related depositary shares have previously been called for redemption, any holder of depositary shares may receive the number of whole shares of the related series of preferred stock and any money or other property represented by those depositary shares after surrendering the related depositary receipts at the corporate trust office of the preferred stock depositary. Holders of depositary shares making these withdrawals will be entitled to receive whole shares of preferred stocklisted on the basis set forth in the prospectus supplement or other offering materials for that series of preferred stock.

However, holders of whole shares of preferred stock will not be entitled to deposit that preferred stockNYSE under the deposit agreement or to receive depositary shares for that preferred stock after withdrawal. If the depositary shares surrendered by the holder in connection with withdrawal exceed the number of depositary shares that represent the number of whole shares of preferred stock to be withdrawn, the preferred stock depositary will deliver to that holder at the same time new depositary receipts evidencing the excess number of depositary shares.

Voting Deposited Preferred Stock

When the preferred stock depositary receives notice of any meeting at which the holders of any series of deposited preferred stock are entitled to vote, the preferred stock depositary will mail the information contained in the notice to the record holders of the depositary shares relating to the applicable series of preferred stock. Each record holder of the depositary shares on the record date will be entitled to instruct the preferred stock depositary to vote the amount of the preferred stock represented by the holder’s depositary shares. To the extent possible, the preferred stock depositary will vote the amount of the series of preferred stock represented by depositary shares in accordance with the instructions it receives.

We will agree to take all reasonable actions that the preferred stock depositary determines are necessary to enable the preferred stock depositary to vote as instructed. The preferred stock depositary will vote all shares of any series of preferred stock held by it proportionately with instructions received if it does not receive specific instructions from the holders of depositary shares representing that series of preferred stock.

-11-


Amendment and Termination of the Deposit Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time be amended by agreement between us and the preferred stock depositary. However, any amendment that imposes additional charges or materially and adversely alters the existing rights of the holders of depositary shares will not be effective unless the amendment has been approved by the holders of at least a majority of the affected depositary shares then outstanding. Holders who retain their depositary shares after the amendment becomes effective will be deemed to agree to the amendment and will be bound by the amended deposit agreement. The deposit agreement automatically terminates if:

all outstanding depositary shares have been redeemed;

symbol “NGS.”

each share of preferred stock has been converted into or exchanged for common stock; or


a final distribution in respect of the preferred stock has been made to the holders of depositary shares in connection with any liquidation, dissolution or winding up of our company.

We may terminate the deposit agreement at any time and the preferred stock depositary will give notice of that termination to the record holders of all outstanding depositary receipts not less than 30 days prior to the termination date. In that event, the preferred stock depositary will deliver or make available for delivery to holders of depositary shares, upon surrender of the related depositary receipts, the number of whole or fractional shares of the related series of preferred stock as are represented by those depositary shares.

Charges of Preferred Stock Depositary; Taxes and Other Governmental Charges

No fees, charges and expenses of the preferred stock depositary or any agent of the preferred stock depositary or of any registrar will be payable by any person other than us, except for any taxes and other governmental charges and except as provided in the deposit agreement. If the preferred stock depositary incurs fees, charges or expenses for which it is not otherwise liable at the election of a holder of depositary shares or other person, that holder or other person will be liable for those fees, charges and expenses.

Resignation and Removal of Depositary

The preferred stock depositary may resign at any time by delivering to us notice of its intent to do so, and we may at any time remove the preferred stock depositary. Any resignation or removal will take effect upon the appointment of a successor preferred stock depositary and its acceptance of the appointment. A successor preferred stock depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000.

-12-


Miscellaneous

The preferred stock depositary will forward all reports and communications from us which are delivered to the preferred stock depositary and which we are required to furnish to the holders of the deposited preferred stock.

Neither we nor the preferred stock depositary will be liable if it is prevented or delayed by law or any circumstances beyond its control in performing its obligations under the deposit agreement. Our obligations and that of the preferred stock depositary under the deposit agreement will be limited to performance with honest intentions of our and their duties under the agreement and we and they will not be obligated to prosecute or defend any legal proceeding in respect of any depositary shares, depositary receipts or shares of preferred stock unless satisfactory indemnity is furnished. We and the preferred stock depositary may rely upon written advice of counsel or accountants, or upon information provided by holders of depositary shares or other persons believed to be competent and on documents believed to be genuine.

-13-


DESCRIPTION OF DEBT SECURITIES AND GUARANTEES

General

The Debt Securities may be either our senior debt securities that we(“Senior Debt Securities”) or our subordinated debt securities (“Subordinated Debt Securities”) or a combination of both and may issue may constitute debentures, notes, bondsbe secured or other evidencesunsecured. The Senior Debt Securities and the Subordinated Debt Securities will be issued under separate indentures among us, the Subsidiary Guarantors of indebtedness of Natural Gas Services Group, Inc.,such Debt Securities, if any, and a trustee to be determined (the “Trustee”). Senior Debt Securities will be issued under a “Senior Indenture” and Subordinated Debt Securities will be issued under a “Subordinated Indenture.” Together, the Senior Indenture and the Subordinated Indenture are called “Indentures.”

The Debt Securities may be issued from time to time in one or more series, which may include senior debt securities, subordinated debt securities and senior subordinated debt securities.series. The particular terms of anyeach series of debt securities we may offer, including the extent to which the general terms set forth below may be applicable tothat are offered by a particular series,prospectus supplement will be described in asuch prospectus supplement relatingsupplement.

Unless the Debt Securities are guaranteed by our subsidiaries as described below, the rights of The Company and its creditors, including holders of the Debt Securities, to such series.

Debt securitiesparticipate

-8-


in the assets of any subsidiary upon the latter’s liquidation or reorganization, will be subject to the prior claims of the subsidiary’s creditors, except to the extent that we may issuethe Company may be issued under a senior indenture between us and a trustee, or a subordinated indenture between us and a trustee (collectively, the “indenture”). creditor with recognized claims against such subsidiary.

We have filed formssummarized selected provisions of the indenturesIndentures below. The summary is not complete. The form of each Indenture has been filed with the SEC as exhibitsan exhibit to the registration statement of which this prospectus is a part. If we enter into any revised indenture or indenture supplement, we will file a copy ofpart, and you should read the Indentures for provisions that supplement with the Securities and Exchange Commission.

The following description is a summary of the material provisions of the indenture. It does not restate the indenture in its entirety. The indenture is governed by the Trust Indenture Act of 1939. Themay be important to you. Capitalized terms of the debt securities include those statedused in the indenture and those made part ofsummary have the indenture by reference to the Trust Indenture Act. We urge you to read the indenture because it, and not this description, defines your rights as a holder of the debt securities.

The indenture contains no covenant or provision which affords debt holders protectionmeanings specified in the event of a highly leveraged transaction.

Indentures.

Information You Will Find
General

The Indentures provide that Debt Securities in the Prospectus Supplement

The indenture provides that weseparate series may issue debt securitiesbe issued thereunder from time to time in one or more series by resolution of our board of directors or by means ofwithout limitation as to aggregate principal amount. We may specify a supplemental indenture, and that we may denominate the debt securities and make them payable in foreign currencies. The indenture does not limit themaximum aggregate principal amount for the Debt Securities of debt securities that can be issued thereunder. Theany series. We will determine the terms and conditions of the Debt Securities, including the maturity, principal and interest. Unless indicated in a prospectus supplement forapplicable to a series of debt securitiesDebt Securities, the Debt Securities may be our secured or unsecured obligations.


The Subordinated Debt Securities will be subordinated in right of payment to the prior payment in full of all of our Senior Debt as described under “—Subordination of Subordinated Debt Securities” and in the prospectus supplement applicable to any Subordinated Debt Securities. If the prospectus supplement so indicates, the Debt Securities will be convertible into our common stock.

If specified in the prospectus supplement respecting a particular series of Debt Securities, certain subsidiaries of the Company (each a “Subsidiary Guarantor”) will fully and unconditionally guarantee (the “Subsidiary Guarantee”) that series as described under “—Subsidiary Guarantee” and in the prospectus supplement. Each Subsidiary Guarantee will be an unsecured obligation of the Subsidiary Guarantor. A Subsidiary Guarantee of Subordinated Debt Securities will be subordinated to the Senior Debt of the Subsidiary Guarantor on the same basis as the Subordinated Debt Securities are subordinated to our Senior Debt.

The applicable prospectus supplement will set forth the price or prices at which the Debt Securities to be issued will be offered for sale and will describe the following terms of such Debt Securities:

(1)the title of the Debt Securities;

(2)whether the Debt Securities are Senior Debt Securities or Subordinated Debt Securities and, if Subordinated Debt Securities, the related subordination terms;

(3)whether any Subsidiary Guarantor will provide information relating to the termsa Subsidiary Guarantee of the series of debt securities being offered, which may include:

the title and denominations of the debt securities of the series;

Debt Securities;


(4)any limit on the aggregate principal amount of the debt securities of the series;

Debt Securities;

the

-9-


(5)each date or dates on which the principal and premium, if any, with respect to the debt securities of the series are payable or Debt Securities will be payable;

(6)the method of determination thereof;

interest rate that the rate or rates, which may be fixed or variable, at which the debt securities of the series shallDebt Securities will bear interest, if any, or the method of calculating and/or resetting such rate or rates of interest;

the dates from which such interest shall accrue or the method by which such dates shall be determined and the basis upon which interest shall be calculated;

the interest payment dates for the series of debt securities orDebt Securities;


(7)each place where payments on the method by which such datesDebt Securities will be determined, thepayable;

(8)any terms of any deferral of interest and any right of ours to extend the interest payments periods;

-14-


the place or places where the principal and interest on the series of debt securities will be payable;

the terms and conditions upon which debt securities of the seriesDebt Securities may be redeemed, in whole or in part, at our option or otherwise;

option;

our obligation, if any, to redeem, purchase, or repay debt securities of the series pursuant to

(9)any sinking fund or other specified eventprovisions that would obligate us to redeem or atotherwise repurchase the option of the holders and the terms of any such redemption, purchase, or repayment;

Debt Securities;

the terms, if any, upon which the debt securities of the series may be convertible into or exchanged for other securities, including, among other things, the initial conversion or exchange price or rate and the conversion or exchange period;


if the amount of principal, premium, if any, or interest with respect to the debt securities of the series may be determined with reference to an index or formula, the manner in which such amounts will be determined;

if any payments on the debt securities of the series are to be made in a currency or currencies (or by reference to an index or formula) other than that in which such securities are denominated or designated to be payable, the currency or currencies (or index or formula) in which such payments are to be made and the terms and conditions of such payments;

any changes or additions to the provisions of the indenture dealing with defeasance, including any additional covenants that may be subject to our covenant defeasance option;

the currency or currencies in which payment of the principal and premium, if any, and interest with respect to debt securities of the series will be payable, or in which the debt securities of the series shall be denominated, and the particular provisions applicable thereto in accordance with the indenture;

(10)the portion of the principal amount, of debt securitiesif less than all, of the series whichDebt Securities that will be payable upon declaration of acceleration or provable in bankruptcy orof the method by which such portion or amount shall be determined;

Maturity of the Debt Securities;


(11)whether the debt securities of the series will be secured or guaranteed and, if so, on what terms;

Debt Securities are defeasible;


(12)any addition to or change in the eventsEvents of default with respect toDefault;

(13)whether the debt securities ofDebt Securities are convertible into our common stock and, if so, the series;

terms and conditions upon which conversion will be effected, including the initial conversion price or conversion rate and any adjustments thereto and the conversion period;

the identity of any trustees, authenticating or paying agents, transfer agents or registrars;


the applicability of, and (14)any addition to or change in the covenants currently set forth in the indenture;

the subordination, if any, of the debt securities of the series and terms of the subordination;

whether securities of the series shall be issuable as registered securities or bearer securities (with or without interest coupons), and any restrictionsIndenture applicable to the offering, sale or delivery of such bearer securitiesDebt Securities; and the terms upon which such bearer securities of a series may be exchanged for registered securities, and vice versa; and


(15)any other terms of the debt securitiesDebt Securities not inconsistent with the provisions of the series.

-15-


HoldersIndenture, except as permitted by clause (12) of debt securitiesthe first paragraph under the caption “—Modification and Waiver.”


Debt Securities, including any Debt Securities that provide for an amount less than the principal amount thereof to be due and payable upon a declaration of acceleration of the Maturity thereof (“Original Issue Discount Securities”), may present debt securities for exchangebe sold at a substantial discount below their principal amount. Special United States federal income tax considerations applicable to Debt Securities sold at an original issue discount may be described in the manner, atapplicable prospectus supplement. In addition, special United States federal income tax or other considerations applicable to any Debt Securities that are denominated in a currency or currency unit other than United States dollars may be described in the places, and subjectapplicable prospectus supplement.

Subordination of Subordinated Debt Securities

The indebtedness evidenced by the Subordinated Debt Securities will, to the restrictionsextent set forth in the debt securities,Subordinated Indenture with respect to each series of Subordinated Debt Securities, be subordinated in right of payment to the indenture,prior payment in full of all of our Senior Debt, including the Senior Debt Securities, and it may also be senior in right of payment to all of our
-10-


Subordinated Debt. The prospectus supplement relating to any Subordinated Debt Securities will summarize the subordination provisions of the Subordinated Indenture applicable to that series including:

the applicability and effect of such provisions upon any payment or distribution respecting that series following any liquidation, dissolution or other winding-up, or any assignment for the benefit of creditors or other marshalling of assets or any bankruptcy, insolvency or similar proceedings;

the applicability and effect of such provisions in the event of specified defaults with respect to any Senior Debt, including the circumstances under which and the periods during which we will be prohibited from making payments on the Subordinated Debt Securities; and

the definition of Senior Debt applicable to the Subordinated Debt Securities of that series and, if the series is issued on a senior subordinated basis, the definition of Subordinated Debt applicable to that series.

The prospectus supplement. Wesupplement will provide these servicesalso describe, as of a recent date, the approximate amount of Senior Debt to which the Subordinated Debt Securities of that series will be subordinated.

The failure to make any payment on any of the Subordinated Debt Securities by reason of the subordination provisions of the Subordinated Indenture described in the prospectus supplement will not be construed as preventing the occurrence of an Event of Default with respect to the Subordinated Debt Securities arising from any such failure to make payment.

The subordination provisions described above will not be applicable to payments in respect of the Subordinated Debt Securities from a defeasance trust established in connection with any legal defeasance or covenant defeasance of the Subordinated Debt Securities as described below under “—Legal Defeasance and Covenant Defeasance.”

Subsidiary Guarantee

If specified in the prospectus supplement, one or more of the Subsidiary Guarantors will guarantee the Debt Securities of a series. Unless otherwise indicated in the prospectus supplement, the following provisions will apply to the Subsidiary Guarantee of the Subsidiary Guarantor.

Subject to the limitations described below and in the prospectus supplement, one or more of the Subsidiary Guarantors will jointly and severally, fully and unconditionally guarantee the punctual payment when due, whether at Stated Maturity, by acceleration or otherwise, of all our payment obligations under the Indentures and the Debt Securities of a series, whether for principal of, premium, if any, or interest on the Debt Securities or otherwise (all such obligations guaranteed by a Subsidiary Guarantor being herein called the “Guaranteed Obligations”). The Subsidiary Guarantors will also pay all expenses (including reasonable counsel fees and
-11-


expenses) incurred by the applicable Trustee in enforcing any rights under a Subsidiary Guarantee with respect to a Subsidiary Guarantor.

In the case of Subordinated Debt Securities, a Subsidiary Guarantor’s Subsidiary Guarantee will be subordinated in right of payment to the Senior Debt of such Subsidiary Guarantor on the same basis as the Subordinated Debt Securities are subordinated to our Senior Debt. No payment will be made by any Subsidiary Guarantor under its Subsidiary Guarantee during any period in which payments by us on the Subordinated Debt Securities are suspended by the subordination provisions of the Subordinated Indenture.

Each Subsidiary Guarantee will be limited in amount to an amount not to exceed the maximum amount that can be guaranteed by the relevant Subsidiary Guarantor without rendering such Subsidiary Guarantee voidable under applicable law relating to fraudulent conveyance or fraudulent transfer or similar laws affecting the rights of creditors generally.

Each Subsidiary Guarantee will be a continuing guarantee and will:

(1)remain in full force and effect until either (a) payment in full of all the applicable Debt Securities (or such Debt Securities are otherwise satisfied and discharged in accordance with the provisions of the applicable Indenture) or (b) released as described in the following paragraph;

(2)be binding upon each Subsidiary Guarantor; and

(3)inure to the benefit of, and be enforceable by, the applicable Trustee, the Holders and their successors, transferees and assigns.

In the event that (a) a Subsidiary Guarantor ceases to be a Subsidiary, (b) either legal defeasance or covenant defeasance occurs with respect to the series or (c) all or substantially all of the assets or all of the Capital Stock of such Subsidiary Guarantor is sold, including by way of sale, merger, consolidation or otherwise, such Subsidiary Guarantor will be released and discharged of its obligations under its Subsidiary Guarantee without any further action required on the part of the Trustee or any Holder, and no other person acquiring or owning the assets or Capital Stock of such Subsidiary Guarantor will be required to enter into a Subsidiary Guarantee. In addition, the prospectus supplement may specify additional circumstances under which a Subsidiary Guarantor can be released from its Subsidiary Guarantee.

Form, Exchange and Transfer

The Debt Securities of each series will be issuable only in fully registered form, without coupons, and, unless otherwise specified in the applicable prospectus supplement, only in denominations of $1,000 and integral multiples thereof.

At the option of the Holder, subject to the terms of the applicable Indenture and the limitations applicable to Global Securities, Debt Securities of each series will be exchangeable for other Debt Securities of the same series of any authorized denomination and of a like tenor and aggregate principal amount.
-12-



Subject to the terms of the applicable Indenture and the limitations applicable to Global Securities, Debt Securities may be presented for exchange as provided above or for registration of transfer (duly endorsed or with the form of transfer endorsed thereon duly executed) at the office of the Security Registrar or at the office of any transfer agent designated by us for such purpose. No service charge other thanwill be made for any registration of transfer or exchange of Debt Securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith, but subject tothat connection. Such transfer or exchange will be effected upon the limitations provided inSecurity Registrar or such transfer agent, as the indenture, any board resolution establishing such debt securitiescase may be, being satisfied with the documents of title and identity of the person making the request. The Security Registrar and any applicable indenture supplement.other transfer agent initially designated by us for any Debt securities in bearer form and the coupons, if any, appertaining theretoSecurities will be transferable by delivery.

Senior Debt

We may issue senior debt securities under the indenture and any coupons that will constitute part of our senior debt. Unless otherwise set forthnamed in the applicable indenture supplementprospectus supplement. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each Place of Payment for the Debt Securities of each series.


If the Debt Securities of any series (or of any series and specified tenor) are to be redeemed in part, we will not be required to (1) issue, register the transfer of or exchange any Debt Security of that series (or of that series and specified tenor, as the case may be) during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any such Debt Security that may be selected for redemption and ending at the close of business on the day of such mailing or (2) register the transfer of or exchange any Debt Security so selected for redemption, in whole or in part, except the unredeemed portion of any board resolution establishing such debt securities and describedDebt Security being redeemed in a prospectus supplement,part.

Global Securities

Some or all of the senior debt securitiesDebt Securities of any series may be senior unsecured obligations, ranking equally with allrepresented, in whole or in part, by one or more Global Securities that will have an aggregate principal amount equal to that of our existing and future senior unsecured debt. The senior debt securitiesthe Debt Securities they represent. Each Global Security will be senior to all of our subordinated debt and junior to any secured debt we may incur as to the assets securing such debt.

Subordinated Debt

We may issue subordinated debt securities under the indenture and any coupons that will constitute part of such subordinated debt. These subordinated debt securities will be subordinate and junior in right of payment, to the extent andregistered in the manner set forthname of a Depositary or its nominee identified in the indenture and any applicable indenture supplement, to all of our senior indebtedness.

If this prospectus is being delivered in connection with a series of subordinated debt securities, the accompanying prospectus supplement or the information incorporated by reference will set forth the approximate amount of senior indebtedness, if any, outstanding as of the end of our most recent fiscal quarter.

Senior Subordinated Debt

We may issue senior subordinated debt securities under the indenture and any coupons that will constitute part of our senior subordinated debt. These senior subordinated debt securities will be, to the extent and in the manner set forth in the indenture, subordinate and junior in right of payment to all of our “senior indebtedness” and senior to our other subordinated debt.

Interest Rate

Debt securities that bear interest will do so at a fixed rate or a floating rate. We may sell, at a discount below the stated principal amount, any debt securities which bear no interest or which bear interest at a rate that at the time of issuance is below the prevailing market rate. The relevant prospectus supplement, will describe the special United States federal income tax considerations applicable to:

any discounted debt securities; and

any debt securities issued at par which are treated as having been issued at a discount for United States federal income tax purposes.

-16-


Registered Global Securities

We may issue registered debt securities of a series in the form of onebe deposited with such Depositary or more fully registered global securities. We will deposit the registered global security with a depositarynominee or with a nominee for a depositary identified in the prospectus supplement relating to such series. The global security or global securities will representits custodian and will bear a legend regarding the restrictions on exchanges and registration of transfer thereof referred to below and any such other matters as may be in a denomination or aggregate denominations equalprovided for pursuant to the portionapplicable Indenture.


Notwithstanding any provision of the aggregate principal amount of outstanding registered debt securities of the series toIndentures or any Debt Security described in this prospectus, no Global Security may be represented by the registered global security or securities. Unless it is exchanged in whole or in part for debt securitiesDebt Securities registered, and no transfer of a Global Security in definitivewhole or in part may be registered, form, a registered global security may not be transferred, except as a whole in three cases:

the depositaryname of any Person other than the Depositary for the registered global security to a nominee of the depositary;

by a nominee of the depositary to the depositary or another nominee of the depositary; and

by the depositarysuch Global Security or any nominee of such Depositary unless:


(1)the Depositary has notified us that it is unwilling or unable to continue as Depositary for such Global Security or has ceased to be qualified to act as such as required by the applicable Indenture, and in either case we fail to appoint a successor Depositary within 90 days;

-13-


(2)an Event of Default with respect to the Debt Securities represented by such Global Security has occurred and is continuing and the Trustee has received a written request from the Depositary to issue certificated Debt Securities;

(3)subject to the rules of the depositaryDepositary, we shall have elected to terminate the book-entry system through the Depositary; or

(4)other circumstances exist, in addition to or in lieu of those described above, as may be described in the applicable prospectus supplement.

All certificated Debt Securities issued in exchange for a nominee of the successor.

The prospectus supplement relating to a series of debt securities will describe the specific terms of the depositary arrangement concerningGlobal Security or any portion of that series of debt securities to be represented by a registered global security. We anticipate that the following provisions will generally apply to all depositary arrangements.

Upon the issuance of a registered global security, the depositary will credit, on its book-entry registration and transfer system, the principal amounts of the debt securities represented by the registered global security to the accounts of persons that have accounts with the depositary. These persons are referred to as “participants.” Any underwriters, agents or debtors participating in the distribution of debt securities represented by the registered global security will designate the accounts to be credited. Only participants or persons that hold interests through participantsthereof will be able to beneficially own interestsregistered in a registered global security. The depositary for a global security will maintain records of beneficial ownership interests in a registered global security for participants. Participants or persons that hold through participants will maintain records of beneficial ownership interests in a global security for persons other than participants. These records will besuch names as the only means to transfer beneficial ownership in a registered global security.

The laws of some statesDepositary may require that specified purchasers of securities take physical delivery of the securities in definitive form. These laws may limit the ability of those persons to own, transfer or pledge beneficial interests in global securities.

-17-


Sodirect.


As long as the depositary,Depositary, or its nominee, is the registered ownerholder of a registered global security,Global Security, the depositaryDepositary or itssuch nominee, as the case may be, will be considered the sole owner or holderand Holder of such Global Security and the debt securities represented by the registered global securityDebt Securities that it represents for all purposes under the indenture.Debt Securities and the applicable Indenture. Except as set forth below,in the limited circumstances referred to above, owners of beneficial interests in a registered global security:

mayGlobal Security will not be entitled to have the debt securities represented by a registered global securitysuch Global Security or any Debt Securities that it represents registered in their names;

names, will not receive or be entitled to receive physical delivery of debt securities represented by a registered global securitycertificated Debt Securities in definitive form;exchange for those interests and

will not be considered to be the owners or holdersHolders of debt securities represented by a registered global securitysuch Global Security or any Debt Securities that it represents for any purpose under the indenture.

Accordingly, each person owningDebt Securities or the applicable Indenture. All payments on a beneficial interest in a registered global security must rely on the procedures of the depositary for the registered global security and, if the person is not a participant, on the procedures of the participant through which the person owns its interests, to exercise any rights of a holder under the indenture applicableGlobal Security will be made to the registered global security.

We understand that, under existing industry practices, if we request any action of holders, or if an owner of a beneficial interest in a registered global security desires to give or take any action which a holder is entitled to give or take under the indenture, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take the action, and the participants would authorize beneficial owners owning through the participants to give or take the action or would otherwise act upon the instructions of beneficial owners holding through them.

Payment of Interest on and Principal of Registered Global Securities

We will make principal, premium, if any, and interest payments on debt securities represented by a registered global security registered in the name of a depositary or its nominee to the depositaryDepositary or its nominee, as the registered ownercase may be, as the Holder of the registered global security. The laws of some jurisdictions may require that some purchasers of Debt Securities take physical delivery of such Debt Securities in certificated form. These laws may impair the ability to transfer beneficial interests in a Global Security.


Ownership of beneficial interests in a Global Security will be limited to institutions that have accounts with the Depositary or its nominee (“participants”) and to persons that may hold beneficial interests through participants. In connection with the issuance of any Global Security, the Depositary will credit, on its book-entry registration and transfer system, the respective principal amounts of Debt Securities represented by the Global Security to the accounts of its participants. Ownership of beneficial interests in a Global Security will be shown only on, and the transfer of those ownership interests will be effected only through, records maintained by the Depositary (with respect to participants’ interests) or any such participant (with respect to interests of Persons held by such participants on their behalf). Payments, transfers, exchanges and other matters relating to beneficial interests in a Global Security may be subject to various policies and procedures adopted by the Depositary from time to time. None of Natural Gas Services Group,us, the trustee,Subsidiary Guarantors, the Trustees or any paying agent for debt securities represented by a registered global securitythe agents of us, the Subsidiary Guarantors or the Trustees will have any responsibility or liability for:

for any aspect of the Depositary’s or any participant’s records relating to, or for payments made on account of, beneficial ownership interests in such registered global security;

a Global Security, or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests;

interests.


Payment and Paying Agents

Unless otherwise indicated in the payments to beneficial ownersapplicable prospectus supplement, payment of the global security of amounts paidinterest on a Debt Security on any Interest Payment Date will be made to the depositary or its nominee; or

Person in whose name such

any other matter relating to the actions and practices of the depositary, its nominee or any of its participants.

-14-

We expect that the depositary, upon receipt of any payment of principal, premium or interest in respect of the global security, will immediately credit participants’ accounts with payments in amounts proportionate to their beneficial interests in the principal amount of a registered global security as shown on the depositary’s records. We also expect that payments by participants to owners of beneficial interests in a registered global security held through participants will be governed by standing instructions and customary practices. This is currently the case with the securities held for the accounts of customers registered in “street name.” Such payments will be the responsibility of participants.

-18-


Exchange of Registered Global Securities

We may issue debt securities in definitive form in exchange for the registered global security if both of the following occur:

the depositary for any debt securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Securities Exchange Act of 1934; and

we do not appoint a successor depositary within 90 days.

In addition, we may, at any time, determine not to have any of the debt securities of a series represented byDebt Security (or one or more Predecessor Securities) is registered global securities. In this event,at the close of business on the Regular Record Date for such interest.


Unless otherwise indicated in the applicable prospectus supplement, principal of and any premium and interest on the Debt Securities of a particular series will be payable at the office of such Paying Agent or Paying Agents as we will issue debt securitiesmay designate for such purpose from time to time, except that at our option payment of that seriesany interest on Debt Securities in definitivecertificated form in exchange for allmay be made by check mailed to the address of the registered global security or securities representing those debt securities.

Our Covenants

The indenture includes covenants by us, including among other things that we will make all payments of principal and interest atPerson entitled thereto as such address appears in the times and places required. The board resolution or supplemental indenture establishing each series of debt securities may contain additional covenants, including covenants which could restrict our right to incur additional indebtedness or liens and to take certain actions with respect to our businesses and assets.

Events of Default

Security Register. Unless otherwise indicated in the applicable prospectus supplement, the followingcorporate trust office of the Trustee under the Senior Indenture in The City of New York will be events of default under the indenturedesignated as sole Paying Agent for payments with respect to Senior Debt Securities of each series, and the corporate trust office of debt securities issuedthe Trustee under the indenture:

failureSubordinated Indenture in The City of New York will be designated as the sole Paying Agent for payment with respect to pay when dueSubordinated Debt Securities of each series. Any other Paying Agents initially designated by us for the Debt Securities of a particular series will be named in the applicable prospectus supplement. We may at any interest ontime designate additional Paying Agents or rescind the designation of any debt securityPaying Agent or approve a change in the office through which any Paying Agent acts, except that we will be required to maintain a Paying Agent in each Place of that series that continuesPayment for 30 days;

the Debt Securities of a particular series.

failure

All money paid by us to pay when duea Paying Agent for the payment of the principal of or any premium if any,or interest on any debt securityDebt Security which remains unclaimed at the end of that series;

two years after such principal, premium or interest has become due and payable will be repaid to us, and the Holder of such Debt Security thereafter may look only to us for payment.

default



Consolidation, Merger and Sale of Assets

Unless otherwise specified in the paymentprospectus supplement, we may not consolidate with or merge into, or transfer, lease or otherwise dispose of all or substantially all of our assets to, any sinking fund installmentPerson (a “successor Person”), and may not permit any Person to consolidate with or merge into us, unless:

(1)     the successor Person (if not us) is a corporation, partnership, trust or other entity organized and validly existing under the laws of the United States of America, any State thereof or the District of Columbia and assumes our obligations on the Debt Securities and under the Indentures;

(2)     immediately before and after giving pro forma effect to the transaction, no Event of Default, and no event which, after notice or lapse of time or both, would become an Event of Default, has occurred and is continuing; and

(3)     several other conditions, including any additional conditions with respect to any debt securityparticular Debt Securities specified in the applicable prospectus supplement, are met.
-15-



The successor Person (if not us) will be substituted for us under the applicable Indenture with the same effect as if it had been an original party to such Indenture, and, except in the case of a lease, we will be relieved from any further obligations under such Indenture and the Debt Securities.

Events of Default

Unless otherwise specified in the prospectus supplement, each of the following will constitute an Event of Default under the applicable Indenture with respect to Debt Securities of any series:

(1)failure to pay principal of or any premium on any Debt Security of that series when due, whether or not, in the case of Subordinated Debt Securities, such payment is prohibited by the subordination provisions of the Subordinated Indenture;

(2)failure to pay any interest on any Debt Securities of that series when due, continued for 30 days, whether or not, in the case of Subordinated Debt Securities, such payment is prohibited by the subordination provisions of the Subordinated Indenture;

(3)failure to deposit any sinking fund payment, when due, in respect of any Debt Security of that series, whether or not, in the case of Subordinated Debt Securities, such deposit is prohibited by the subordination provisions of the Subordinated Indenture;

(4)failure to perform or comply with the provisions described under “—Consolidation, Merger and payable.

Sale of Assets” above;


(5)failure to perform any of our other covenants in such Indenture (other than a covenant or agreementincluded in such Indenture solely for the benefit of ours under the indenture or the supplemental indenture with respect toa series other than that series or the debt securities of that series,series), continued for 9060 days after written notice to ushas been given by the trusteeapplicable Trustee, or holdersthe Holders of at least 25% in aggregate principal amount of the outstanding debt securitiesOutstanding Debt Securities of that series, as provided in such Indenture;

(6)any Debt of ours, any Significant Subsidiary or, if a Subsidiary Guarantor has guaranteed the series, such Subsidiary Guarantor, is not paid within any applicable grace period after final maturity or is accelerated by its holders because of a default and the total amount of such Debt unpaid or accelerated exceeds $25.0 million; provided, however, that if any such default is cured or waived or any such acceleration rescinded, or such Debt is repaid, within a period of 30 days from the continuation of such default beyond the applicable grace period or the occurrence of such acceleration, as the case may be, such Event of Default and any consequential acceleration of the Debt Securities shall be automatically rescinded, so long as such rescission does not conflict with any judgment or decree;
-16-



(7)any judgment or decree for the payment of money in excess of $25.0 million (net of any amounts covered by insurance or a binding indemnity agreement) is entered against us, any Significant Subsidiary or, if a Subsidiary Guarantor has guaranteed the series, to which the covenantsuch Subsidiary Guarantor, remains outstanding for a period of 60 consecutive days following entry of such judgment and is not discharged, waived or agreement relates;

stayed;


(8)certain events of bankruptcy, insolvency or similar proceedingsreorganization affecting us, and our subsidiaries; and

-19-


any other event of default specified inSignificant Subsidiary or, if a Subsidiary Guarantor has guaranteed the series, such Subsidiary Guarantor; and


(9)if any supplemental indenture under whichSubsidiary Guarantor has guaranteed such series, the Subsidiary Guarantee of debt securitiesany such Subsidiary Guarantor is issued.

Except asheld by a final non-appealable order or judgment of a court of competent jurisdiction to certain eventsbe unenforceable or invalid or ceases for any reason to be in full force and effect (other than in accordance with the terms of bankruptcy, insolvency or similar proceedings affecting us and except as provided in the applicable prospectus supplement, ifIndenture) or any eventSubsidiary Guarantor or any Person acting on behalf of default shall occur and be continuingany Subsidiary Guarantor denies or disaffirms such Subsidiary Guarantor’s obligations under its Subsidiary Guarantee (other than by reason of a release of such Subsidiary Guarantor from its Subsidiary Guarantee in accordance with the terms of the applicable Indenture).


If an Event of Default (other than an Event of Default with respect to Natural Gas Services Group, Inc. described in clause (8) above) with respect to the Debt Securities of any series of debt securities underat the indenture,time Outstanding occurs and is continuing, either the trusteeapplicable Trustee or the holdersHolders of at least 25% in aggregate principal amount of outstanding debt securitiesthe Outstanding Debt Securities of that series by notice as provided in the Indenture may declare the principal amount of the Debt Securities of that series (or, in the case of any Debt Security that is an Original Issue Discount Debt Security, such portion of the principal amount of such Debt Security as may be specified in the terms of such Debt Security) to be due and payable immediately, together with any accrued and unpaid interest thereon. If an Event of Default with respect to Natural Gas Services Group, Inc. described in clause (8) above with respect to the Debt Securities of any series may accelerateat the maturitytime Outstanding occurs, the principal amount of all debt securitiesthe Debt Securities of that series (or, in the case of any such series. Upon certain events of bankruptcy, insolvencyOriginal Issue Discount Security, such specified amount) will automatically, and without any action by the applicable Trustee or similar proceedings affecting us, the principal, premium, if any and interest on all debt securities of each series shall beHolder, become immediately due and payable.

payable, together with any accrued and unpaid interest thereon. After any such acceleration and its consequences, but before a judgment or decree based on acceleration, has been obtained by the trustee, the holdersHolders of a majority in aggregate principal amount of each affectedthe Outstanding Debt Securities of that series of debt securities may, waive all defaults with respect to such series andunder certain circumstances, rescind and annul such acceleration if all eventsEvents of default,Default with respect to that series, other than the non-payment of accelerated principal (or other specified amount), have been cured or waived as provided in the applicable Indenture. For information as to waiver of defaults, see “—Modification and Waiver” below.


Subject to the provisions of the Indentures relating to the duties of the Trustees in case an Event of Default has occurred and is continuing, no Trustee will be under any obligation to exercise any of its rights or otherwise remedied.

No holderpowers under the applicable Indenture at the request or direction of any debt securitiesof the Holders, unless such Holders have offered to such Trustee reasonable security or

-17-


indemnity. Subject to such provisions for the indemnification of the Trustees, the Holders of a majority in principal amount of the Outstanding Debt Securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the Trustee or exercising any trust or power conferred on the Trustee with respect to the Debt Securities of that series.

No Holder of a Debt Security of any series will have any right to institute any proceeding with respect to the indentureapplicable Indenture, or for the appointment of a receiver or a trustee, or for any other remedy under the indenture, unless thereunder, unless:

(1)such holder shall haveHolder has previously given to the trusteeTrustee under the applicable Indenture written notice of a continuing eventEvent of default andDefault with respect to the holdersDebt Securities of that series;

(2)the Holders of at least 25% in aggregate principal amount of the outstanding debt securitiesOutstanding Debt Securities of the relevantthat series shall have made written request, and such Holder or Holders have offered reasonable security or indemnity, satisfactory to the trusteeTrustee to institute such proceeding as trustee,trustee; and

(3)the trustee shallTrustee has failed to institute such proceeding and has not have received from the holdersHolders of a majority in aggregate principal amount of the outstanding debt securitiesOutstanding Debt Securities of suchthat series a direction inconsistent with such request, and shall have failed to institute such proceeding within 60 days. days after such notice, request and offer.

However, such limitations do not apply to a suit instituted by a holderHolder of a debt securityDebt Security for the enforcement of payment of the principal of andor any premium if any, or interest on such debt securityDebt Security on or after the respectiveapplicable due dates expresseddate specified in such debt security.

Debt Security or, if applicable, to convert such Debt Security.

Supplemental Indentures

We will be required to furnish to each Trustee annually a statement by certain of our officers as to whether or not we, to their knowledge, are in default in the performance or observance of any of the terms, provisions and conditions of the trusteeapplicable Indenture and, if so, specifying all such known defaults.

Modification and Waiver

We may at any time and from time to time,modify or amend an Indenture without prior notice to orthe consent of any holders of debt securities after issuancethe Debt Securities in certain circumstances, including:

(1)to evidence the succession under the Indenture of another Person to us or any Subsidiary Guarantor and to provide for its assumption of our or such debt securities, enter into one or more supplemental indenturesSubsidiary Guarantor’s obligations to among other things:

holders of Debt Securities;

add guarantees

(2)to or secure any series of debt securities;

add any additional Eventscovenants of Default;

provideus or the Subsidiary Guarantors for the succession of another person pursuant to the provisions of the indenture relating to consolidations, mergers and sales of assets and the assumption by such successor of our covenants, agreements, and obligations, or to otherwise comply with the provisions of the indenture relating to consolidations, mergers, and sales of assets;

surrender any right or power conferred upon us under the indenture or to add to our covenants further covenants, restrictions, conditions or provisions for the protectionbenefit of the holders of all or any series of debt securities;

Debt Securities or to surrender any right or power under the applicable Indenture conferred upon us or any Subsidiary Guarantor;

-20-

-18-



(3)to add any additional Events of Default with respect to all or any series of Debt Securities;

(4)to provide for uncertificated notes in addition to, or in place of, certificated notes;

(5)to secure the Debt Securities;

(6)to establish the form or terms of any series of Debt Securities;

(7)to evidence and provide for the acceptance of appointment under the Indenture of a successor Trustee;

(8)to cure any ambiguity, defect or inconsistency;

(9)to correct or supplement any provision contained add Subsidiary Guarantors;

(10)in the indenture,case of any Subordinated Debt Security, to make any change in the subordination provisions that limits or terminates the benefits applicable to any supplemental indenture or in any debt securitiesholder of Senior Debt;

(11)to make other changes that may be defective or inconsistent with any other provision contained therein, so long as any such action doesdo not adversely affect the interests of the holdersHolders of debt securitiesDebt Securities of any series issued thereunder in any material respect;

or


(12)to add orto, change or eliminate any of the provisions of the indenture to extent as shall be necessary to permitapplicable Indenture in respect of one or facilitate the issuance of debt securities in bearer form, registrable or not registrable as to principal, and with or without interest coupons;

add to or change any of the provisions of the indenture to permit the defeasance and discharge of anymore series of debt securities pursuant to the indenture;

change, or eliminate any of the provisions of the indentureDebt Securities, provided that any such addition, change or elimination (a) shall become effective only when there are no debt securities outstandingneither (i) apply to any Debt Security of any series created prior to the execution of such supplemental indenture

evidence and provide forentitled to the acceptancebenefit of appointment by a successor or separate trustee; and

establishsuch provision nor (ii) modify the form or termsrights of debt securitiesthe Holder of any seriessuch Debt Security with respect to such provision or (b) shall become effective only when there is no such Debt Security Outstanding.


Other modifications and to make any change that does not adversely affectamendments of an Indenture may be made by us, the interests ofSubsidiary Guarantors, if applicable, and the holders of debt securities.

Withapplicable Trustee with the consent of the holdersHolders of at least a majority in principal amount of debt securitiesthe Outstanding Debt Securities of each series affected by such supplemental indenture (each series voting as one class), we and the trustee may enter into onemodification or more supplemental indentures for the purpose of adding any provisions to or changing in any manner or eliminating any of the provisions of the indenture or modifying in any manner the rights of the holders of debt securities of each such series.

Notwithstanding our rights and the rights of the trustee to enter into one or more supplemental indentures with the consent of the holders of debt securities of the affected series as described above,amendment; provided, however, that no such supplemental indenture to be entered into after issuance of the debt securities shall,modification or amendment may, without the consent of the holderHolder of each outstanding debt security of theOutstanding Debt Security affected series, among other things:

thereby:


(1)change the final maturityStated Maturity of the principal of, or any installment of principal of or interest on, any debt securities;

Debt Security;


(2)reduce the principal amount of, or any debt securitiespremium or the rate of interest on, any debt securities;

Debt Security;


(3)reduce the amount of principal of an Original Issue Discount Security or any other Debt Security payable upon acceleration of the Maturity thereof;

-19-


(4)change the place or currency in whichof payment of principal of, or any debt securities are payable;

premium or interest on, any Debt Security;

release

(5)impair the right to institute suit for the enforcement of any security interest that may have been grantedpayment due on or any conversion right with respect to such debt securities;

any Debt Security;

impair

(6)modify the rightsubordination provisions in the case of the holders to conductSubordinated Debt Securities, or modify any conversion provisions, in either case in a proceeding for any remedy availablemanner adverse to the trustee;

Holders of such Debt Securities;


(7)except as provided in the applicable Indenture, release the Subsidiary Guarantee of a Subsidiary Guarantor;

(8)reduce the percentage in principal amount of Outstanding Debt Securities of any series, the consent of debt securities whose holders must consent to anHolders is required for modification or amendment or supplemental indenture;

modify the ranking or priority of the securities;

Indenture;


(9)reduce any premium payable upon the redemptionpercentage in principal amount of Outstanding Debt Securities of any debt securitiesseries necessary for waiver of compliance with certain provisions of the Indenture or change the time at which any debt security may be redeemed; or

-21-


make any change that adversely affects the relative rightsfor waiver of holders of subordinated debt securitiescertain defaults;


(10)modify such provisions with respect to senior debt securities.

modification, amendment or waiver; or

Satisfaction and Discharge
(11)following the making of the Indenture; Defeasance

Exceptan offer to the extent set forthpurchase Debt Securities from any Holder that has been made pursuant to a covenant in a supplemental indenturesuch Indenture, modify such covenant with respect to such offer in a manner adverse to such Holder.


The Holders of a majority in principal amount of the Outstanding Debt Securities of any series may waive compliance by us with certain restrictive provisions of debt securities,the applicable Indenture. The Holders of a majority in principal amount of the Outstanding Debt Securities of any series may waive any past default under the applicable Indenture, except a default in the payment of principal, premium or interest and certain covenants and provisions of the Indenture which cannot be amended without the consent of the Holder of each Outstanding Debt Security of such series.

Each of the Indentures provides that in determining whether the Holders of the requisite principal amount of the Outstanding Debt Securities have given or taken any direction, notice, consent, waiver or other action under such Indenture as of any date:

(1)the principal amount of an Original Issue Discount Security that will be deemed to be Outstanding will be the amount of the principal that would be due and payable as of such date upon acceleration of Maturity to such date;

(2)if, as of such date, the principal amount payable at the Stated Maturity of a Debt Security is not determinable (for example, because it is based on an index), the principal amount of such Debt Security deemed to be Outstanding as of such date will be an amount determined in the manner prescribed for such Debt Security;
-20-



(3)the principal amount of a Debt Security denominated in one or more foreign currencies or currency units that will be deemed to be Outstanding will be the United States-dollar equivalent, determined as of such date in the manner prescribed for such Debt Security, of the principal amount of such Debt Security (or, in the case of a Debt Security described in clause (1) or (2) above, of the amount described in such clause); and

(4)certain Debt Securities, including those owned by us, any Subsidiary Guarantor or any of our other Affiliates, will not be deemed to be Outstanding.

Except in certain limited circumstances, we at our election,will be entitled to set any day as a record date for the purpose of determining the Holders of Outstanding Debt Securities of any series entitled to give or take any direction, notice, consent, waiver or other action under the applicable Indenture, in the manner and subject to the limitations provided in the Indenture. In certain limited circumstances, the Trustee will be entitled to set a record date for action by Holders. If a record date is set for any action to be taken by Holders of a particular series, only persons who are Holders of Outstanding Debt Securities of that series on the record date may dischargetake such action. To be effective, such action must be taken by Holders of the indenturerequisite principal amount of such Debt Securities within a specified period following the record date. For any particular record date, this period will be 180 days or such other period as may be specified by us (or the Trustee, if it set the record date), and the indenture shall generallymay be shortened or lengthened (but not beyond 180 days) from time to time.

Satisfaction and Discharge

Each Indenture will be discharged and will cease to be of any further effect with respectas to all outstanding Debt Securities of any series issued thereunder, when:

(1)either:

(a)    all outstanding Debt Securities of that series of debt securities if (a) wethat have been authenticated (except lost, stolen or destroyed Debt Securities that have been replaced or paid and Debt Securities for whose payment money has theretofore been deposited in trust and thereafter repaid to us) have been delivered to the trusteeTrustee for cancellationcancellation; or

(b)    all debt securitiesoutstanding Debt Securities of that series (with certain limited exceptions) or (b) all debt securities of that serieshave been not previously delivered to the trusteeTrustee for cancellation shall have become due and payable or are by their terms towill become due and payable at their Stated Maturity within one year or are to be called for redemption within one year under arrangements satisfactory to the Trustee and in any case we have irrevocably deposited with the trusteeTrustee as trust funds money in an amount sufficient, without consideration of any reinvestment of interest, to pay the entire amount sufficient to pay at maturity or upon redemption allindebtedness of such debt securities.

In addition, we have a “legal defeasance option” (pursuant to which we may terminate, with respectDebt Securities not delivered to the debt securities of a particular series, all of our obligations under such debt securities and the indenture with respect to such debt securities) and a “covenant defeasance option” (pursuant to which we may terminate, with respect to the debt securities of a particular series, our obligations with respect to such debt securities under certain specified covenants contained in the indenture). If we exercise our legal defeasance option with respect to a series of debt securities, payment of such debt securities may not be accelerated because of an event of default. If we exercise our covenant defeasance option with respect to a series of debt securities, payment of such debt securities may not be accelerated because of an event of default related to the specified covenants.

We may exercise our legal defeasance option or our covenant defeasance option with respect to the debt securities of a series only if we irrevocably deposit in trust with the trustee cash or U.S. government obligations (as defined in the indenture)Trustee for the payment ofcancellation, for principal, premium, if any, and accrued interest to the Stated Maturity or redemption date;

-21-



(2)we have paid or caused to be paid all other sums payable by us under the Indenture with respect to the Debt Securities of that series; and

(3)we have delivered an Officers’ Certificate and an Opinion of Counsel to the Trustee stating that all conditions precedent to satisfaction and discharge of the Indenture with respect to the Debt Securities of that series have been satisfied.

Legal Defeasance and Covenant Defeasance

To the extent indicated in the applicable prospectus supplement, we may elect, at our option at any time, to have our obligations discharged under provisions relating to defeasance and discharge of indebtedness, which we call “legal defeasance,” or relating to defeasance of certain restrictive covenants applied to the Debt Securities of any series, which we call “covenant defeasance.”

Legal Defeasance. The Indentures provide that, upon our exercise of our option (if any) to have the legal defeasance provisions applied to any series of Debt Securities, we and, if applicable, each Subsidiary Guarantor will be discharged from all our obligations, and, if such Debt Securities are Subordinated Debt Securities, the provisions of the Subordinated Indenture relating to subordination will cease to be effective, with respect to such debt securitiesDebt Securities (except for certain obligations to maturityconvert, exchange or redemption, asregister the casetransfer of Debt Securities, to replace stolen, lost or mutilated Debt Securities, to maintain paying agencies and to hold moneys for payment in trust) upon the deposit in trust for the benefit of the Holders of such Debt Securities of money or U.S. Government Obligations, or both, which, through the payment of principal and interest in respect thereof in accordance with their terms, will provide money in an amount sufficient (in the opinion of a nationally recognized firm of independent public accountants) to pay the principal of and any premium and interest on such Debt Securities on the respective Stated Maturities in accordance with the terms of the applicable Indenture and such Debt Securities. Such defeasance or discharge may be. In addition, to exercise either of our defeasance options, occur only if, among other things:

(1)we must comply with certain other conditions, including the deliveryhave delivered to the trusteeapplicable Trustee an Opinion of an opinion of counselCounsel to the effect that we have received from, or there has been published by, the holders of debt securitiesUnited States Internal Revenue Service a ruling, or there has been a change in tax law, in either case to the effect that Holders of such seriesDebt Securities will not recognize income, gain or loss for Federalfederal income tax purposes as a result of such deposit and legal defeasance and will be subject to Federalfederal income tax on the same amounts,amount, in the same manner and at the same times as would have been the case if such deposit and legal defeasance hadwere not to occur;

(2)no Event of Default or event that with the passing of time or the giving of notice, or both, shall constitute an Event of Default shall have occurred and be continuing at the time of such deposit (other than a default or an Event of Default resulting from the borrowing of funds to be applied to such deposit (and any similar concurrent deposit relating to other Indebtedness) and the granting of liens to secure such borrowing) or, with respect to any Event of Default described in
-22-


clause (8) under “—Events of Default,” at any time until 121 days after such deposit;

(3)such deposit and legal defeasance will not result in a breach or violation of, or constitute a default under, any agreement or instrument (other than the applicable Indenture) to which we are a party or by which we are bound; and

(4)in the case of legalSubordinated Debt Securities, at the time of such deposit, no default in the payment of all or a portion of principal of (or premium, if any) or interest on any Senior Debt shall have occurred and be continuing, no event of default shall have resulted in the acceleration of any Senior Debt and no other event of default with respect to any Senior Debt shall have occurred and be continuing permitting after notice or the lapse of time, or both, the acceleration thereof.

Covenant Defeasance. The Indentures provide that, upon our exercise of our option (if any) to have the covenant defeasance only,provisions applied to any Debt Securities, we may fail to comply with certain restrictive covenants (but not with respect to conversion, if applicable), including those that may be described in the applicable prospectus supplement, and the occurrence of certain Events of Default, which are described above in clause (5) (with respect to such opinionrestrictive covenants) and clauses (6), (7) and (9) under “Events of counselDefault” and any that may be described in the applicable prospectus supplement, will not be deemed to either be or result in an Event of Default and, if such Debt Securities are Subordinated Debt Securities, the provisions of the Subordinated Indenture relating to subordination will cease to be effective, in each case with respect to such Debt Securities. In order to exercise such option, we must be based on a ruling from the Internal Revenue Service or other change in applicable Federal income tax law).

The trustee will holddeposit, in trust for the cashbenefit of the Holders of such Debt Securities, money or U.S. government obligations deposited with it as described above and will apply the deposited cash and the proceeds from deposited U.S. government obligations toGovernment Obligations, or both, which, through the payment of principal premium, if any, and interest in respect thereof in accordance with respecttheir terms, will provide money in an amount sufficient (in the opinion of a nationally recognized firm of independent public accountants) to pay the principal of and any premium and interest on such Debt Securities on the respective Stated Maturities in accordance with the terms of the applicable Indenture and such Debt Securities. Such covenant defeasance may occur only if we have delivered to the debt securitiesapplicable Trustee an Opinion of Counsel to the defeased series. In the caseeffect that Holders of subordinated debt securities, the money and U.S. government obligations held in trustsuch Debt Securities will not be subject to the subordination provisions of the indenture.

-22-


Mergers, Consolidations and Certain Sales of Assets

Under the proposed form of indenture, we may not (1) consolidate withrecognize gain or merge into any other person or entity or permit any other person or entity to consolidate with or merge into us in a transaction in which we are not the surviving entity, or (2) transfer, lease or dispose of all or substantially all of our assets to any other person or entity unless:

the resulting, surviving or transferee entity shall be a corporation organized and existing under the laws of the United States or any state thereof and such resulting, surviving or transferee entity shall expressly assume, by supplemental indenture, all of our obligations under the debt securities and the indenture;

immediately after giving effect to such transaction (and treating any indebtedness which becomes an obligation of the resulting, surviving or transferee entityloss for federal income tax purposes as a result of such transactiondeposit and covenant defeasance and will be subject to federal income tax on the same amount, in the same manner and at the same times as havingwould have been incurred bythe case if such entitydeposit and covenant defeasance were not to occur, and the requirements set forth in clauses (2), (3) and (4) above are satisfied. If we exercise this option with respect to any series of Debt Securities and such Debt Securities were declared due and payable because of the occurrence of any Event of Default, the amount of money and U.S. Government Obligations so deposited in trust would be sufficient to pay amounts due on such Debt Securities at the time of their respective Stated Maturities but may not be sufficient to pay amounts due on such transaction), no defaultDebt Securities upon any acceleration resulting from such Event of Default. In such case, we would remain liable for such payments.


If we exercise either our legal defeasance or event of default would occur or be continuing; and

covenant defeasance option, any Subsidiary Guarantee will terminate.

we shall have delivered to the trustee an officers’ certificate and an opinion of counsel, each stating that such consolidation, merger or transfer and such supplemental indenture (if any) comply with the indenture.


Governing Law

The indenture and the debt securities will be governed by the laws of the State of New York.

No Personal Liability of Directors, Officers, Employees and ShareholdersStockholders
-

23-




No director, officer, employee, incorporator, stockholder, member, manager, partner or shareholdertrustee of Natural Gas Services Group,the Company or any Subsidiary Guarantor, as such, shall have any liability for any obligations of Natural Gas Services Groupthe Company or any Subsidiary Guarantor under the debt securitiesDebt Securities, the Indentures or the indentureany Subsidiary Guarantees or for any claim based on, in respect of, or by reason of, such obligations or their creation, solely by reason of his, her, or its status as director, officer, incorporator or shareholder of Natural Gas Services Group.creation. By accepting a debt security,Debt Security, each holder waivesHolder shall be deemed to have waived and releasesreleased all such liability, but only such liability. The waiver and release areshall be a part of the consideration for issuancethe issue of the debt securities. Nevertheless, suchDebt Securities. The waiver may not be effective to waive liabilities under the federal securities laws, and it has beenis the view of the Securities and Exchange CommissionSEC that such a waiver is against public policy.

Conversion
Notices

Notices to Holders of Debt Securities will be given by mail to the addresses of such Holders as they may appear in the Security Register.

Title

    We, the Subsidiary Guarantors, the Trustees and any agent of us, the Subsidiary Guarantors or Exchange Rightsa Trustee may treat the Person in whose name a Debt Security is registered as the absolute owner of the Debt Security (whether or not such Debt Security may be overdue) for the purpose of making payment and for all other purposes.

Any debt securities issued

Governing Law

The Indentures and the Debt Securities will be governed by, and construed in accordance with, the law of the State of New York.

The Trustee

We will enter into the Indentures with a Trustee that is qualified to act under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”), and with any other Trustees chosen by us and appointed in a supplemental indenture for a particular series of Debt Securities. We may be convertible intomaintain a banking relationship in the ordinary course of business with our Trustee and one or exchangeable for sharesmore of our equity securities. Theits affiliates.

Resignation or Removal of Trustee. If the Trustee has or acquires a conflicting interest within the meaning of the Trust Indenture Act, the Trustee must either eliminate its conflicting interest or resign, to the extent and in the manner provided by, and subject to the provisions of, the Trust Indenture Act and the applicable Indenture. Any resignation will require the appointment of a successor Trustee under the applicable Indenture in accordance with the terms and conditions of such conversionIndenture.

The Trustee may resign or exchange will be set forth in the applicable prospectus supplement. Such terms may include, among others, the following:

the conversion or exchange price;

the conversion or exchange period;

-23-


provisions regarding our ability or that of the holder to convert or exchange the debt securities;

events requiring adjustment to the conversion or exchange price; and

provisions affecting conversion or exchange in the event of our redemption of such debt securities.

Concerning the Trustee

The indenture provides that there may be more than one trusteeremoved by us with respect to one or more series of debt securities. If there are different trustees for different series of debt securities, each trustee willDebt Securities and a successor Trustee may be a trusteeappointed to act with respect to any such series. The holders of a trust under a supplemental indenture separate and apart frommajority in aggregate principal amount of the trust administered byDebt Securities of any other trustee under such indenture. Except as otherwise indicated in this prospectus or any prospectus supplement, any action permitted to be taken by a trusteeseries may be taken byremove the trustee onlyTrustee with respect to the one or more seriesDebt Securities of debt securities for which itsuch series.

-24-



Limitations on Trustee if It is the trustee under an indenture. Any trustee under the indenture or a supplemental indenture may resign or be removed with respect to one or more series of debt securities. All payments of principal of, premium, if any, and interest on, and all registration, transfer, exchange, authentication and delivery of (including authentication and delivery on original issuance of the debt securities), the debt securities of a seriesOur Creditor. Each Indenture will be effected by the trustee with respect to such series at an office designated by the trustee.

The indenture containscontain certain limitations on the right of the trustee, shouldTrustee, in the event that it become abecomes our creditor, of Natural Gas Services Group, to obtain payment of claims in certain cases, or to realize on certain property received in respect of any such claim as security or otherwise. If


Certificates and Opinions to Be Furnished to Trustee. Each Indenture will provide that, in addition to other certificates or opinions that may be specifically required by other provisions of an Indenture, every application by us for action by the trustee acquiresTrustee must be accompanied by an interestofficers’ certificate and an opinion of counsel stating that, conflictsin the opinion of the signers, all conditions precedent to such action have been complied with by us.

DESCRIPTION OF DEPOSITARY SHARES

We may offer fractional interests in shares of preferred stock rather than full shares of preferred stock. In that event, depositary receipts will be issued to evidence depositary shares, each of which will represent a fraction of a share of a particular series of preferred stock, as described in the prospectus supplement relating to the particular issue of depositary shares.

The shares of preferred stock represented by depositary shares will be deposited under a deposit agreement between us and a depositary that is a bank or trust company, as depositary, that we select as set forth in the prospectus supplement relating to the particular issue of depositary shares. Unless otherwise specified in the prospectus supplement relating to a particular issue of depositary shares, each owner of a depositary share will be entitled, in proportion to the applicable fraction of a share of preferred stock represented by such depositary share, to all the rights and preferences of the shares of preferred stock represented by such depositary share, including dividend and liquidation rights and any right to convert the shares of preferred stock into common stock.

We will describe the terms of any depositary shares we offer and the related depositary agreement, as well as the terms of the shares of preferred stock represented thereby, in the prospectus supplement relating to the particular issue of depositary shares.

DESCRIPTION OF WARRANTS

We may issue warrants that entitle the holder to purchase common stock, preferred stock, debt securities or other securities. Warrants may be issued independently or together with common stock, preferred stock, debt securities or other securities offered by any prospectus supplement and may be attached to or separate from any such offered securities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, as warrant agent, all as will be set forth in the prospectus supplement relating to the particular issue of warrants. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any dutiesholders of warrants or beneficial owners of warrants.

-25-


The following summary of certain provisions of the warrants does not purport to be complete and is subject to, and is qualified in its entirety by reference to, all provisions of the warrant agreements.

Reference is made to the prospectus supplement relating to the particular issue of warrants offered pursuant to such prospectus supplement for the terms of and information relating to such warrants, including, where applicable:

the number of shares of common stock purchasable upon the exercise of warrants to purchase common stock and the price at which such number of shares of common stock may be purchased upon such exercise;

the number of shares and series of preferred stock purchasable upon the exercise of warrants to purchase preferred stock and the price at which such number of shares of such series of preferred stock may be purchased upon such exercise;

the designation, aggregate principal amount, denominations and terms of the series of debt securities purchasable upon exercise of warrants to purchase debt securities and the price at which such debt securities may be purchased upon such exercise;

the number of other securities purchasable upon exercise of the warrants to purchase such other securities and the price at which such securities may be purchased upon exercise;

the date on which the right to exercise such warrants shall commence and the date on which such right shall expire;

United States federal income tax consequences applicable to such warrants;

the amount of warrants outstanding as of the most recent practicable date; and

any other terms of such warrants.

Warrants will be offered and exercisable for United States dollars only. Warrants will be issued in registered form only. The exercise price for warrants will be subject to adjustment in accordance with respectthe applicable prospectus supplement.

Each warrant will entitle the holder thereof to purchase such number of shares of common stock, preferred stock or other securities or such principal amount of debt securities at such exercise price as shall in each case be set forth in, or calculable from, the prospectus supplement relating to the warrants, which exercise price may be subject to adjustment upon the occurrence of certain events as set forth in such prospectus supplement. After the close of business on the expiration date, or such later date to which such expiration date may be extended by us, unexercised warrants will become void. The place or places where, and the manner in which, warrants may be exercised shall be specified in the prospectus supplement relating to such warrants.
-26-



Prior to the exercise of any warrants to purchase common stock, preferred stock, debt securities or other securities, holders of such warrants will not have any of the rights of holders of such common stock, preferred stock, debt securities or other securities, as the case may be, purchasable upon such exercise, including the right to receive payments of dividends, if any, on the common stock or preferred stock purchasable upon such exercise, or to receive payments of principal of, premium, if any, or interest, if any, on the debt securities the trustee is requiredpurchasable upon such exercise or to either resign or eliminate such conflicting interest to the extent andenforce covenants in the manner provided by theapplicable indenture.

Limitations on Issuance of Bearer Debt Securities

Debt securities in bearer form are subject to special U.S. tax requirements and may not be offered, sold, or delivered within the United States or its possessions or to a U.S. person, except in certain transactions permitted by U.S. tax regulations. Investors should consult the relevant prospectus supplement, in the event that bearer debt securities are issued for special procedures and restrictions that will apply to such an offering.

-24-


DESCRIPTION OF RIGHTS

We may issue rights to purchase debt securities,our common stock, preferred stock, common stockdebt securities or depositary shares. These rights may be issuedoffered independently or together with any other security offered hereby and may or may not be transferable by the shareholderstockholder receiving the rights in such offering. In connection with any offering of such rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after such offering.

Each series of


The prospectus supplement relating to any rights we offer, if any, will, be issued under a separate rights agreement which we will enter into with a bank or trust company, as rights agent, all as set forth into the extent applicable, prospectus supplement. The rights agent will act solely as our agent in connection with the certificatesinclude specific terms relating to the rights and will not assumeoffering, including some or all of the following:

the price, if any, obligationfor the rights;

the exercise price payable for our common stock, preferred stock, debt securities or relationshipdepositary shares upon the exercise of agency or trust with any holders of rights certificates or beneficial owners of rights. We will file the rights agreement and the rights certificates relating to each series of rights with the Securities and Exchange Commission, and incorporate them by reference as an exhibit to the registration statement of which this prospectus is a part on or before the time we issue a series of rights.

The applicable prospectus supplement will describe the specific terms of any offering of rights for which this prospectus is being delivered, including the following:

the date of determining the shareholders entitled to the rights distribution;

rights;


the number of rights issued or to be issued to each shareholder;

stockholder;

the exercise price payable for each share of debt securities, preferred stock, common stock or other securities upon the exercise of the rights;


the number and terms of the shares ofour common stock, preferred stock, debt securities preferred stock, common stock or other securitiesdepositary shares which may be purchased per each right;


the extent to which the rights are transferable;


any other terms of the rights, including the terms, procedures and limitations relating to the exchange and exercise of the rights;

the date on which the holder’s abilityright to exercise the rights shall commence, and the date on which the rights shall expire;


the extent to which the rights may include an over-subscription privilege with respect to unsubscribed securities;

securities or an over-allotment privilege to the extent the securities are fully subscribed; and


if applicable, the material terms of any standby underwriting or purchase arrangement enteredwhich we may enter into by us in connection with the offering of such rights; and

rights.

any other terms of the rights, including the terms, procedures, conditions and limitations relating to the exchange and exercise of the rights.


-27-


The description in the applicable prospectus supplement of any rights that we may offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable rights certificate, which will be filed with the SecuritiesSEC if we offer rights. We urge you to read the applicable rights certificate and Exchange Commission.

-25-


any applicable prospectus supplement in their entirety.

DESCRIPTION OF UNITS

We may issue units consistingcomprised of one or more debtof the other classes of securities sharesdescribed in this prospectus in any combination. Each unit will be issued so that the holder of common stock or preferred stock, warrants or any combinationthe unit is also the holder of such securities.each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The units may be issued under unit agreements to be entered into between us and a unit agent, as detailed in the prospectus supplement relating to the units being offered. The prospectus supplement will describe the terms of any units we issue, including as applicable:

describe:


the designation and terms of the units and of the securities included incomprising the units;

units, including whether and under what circumstances the securities comprising the units may be held or transferred separately;


a description of the terms of any provisionunit agreement governing the units;

a description of the provisions for the issuance, payment, settlement, transfer or exchange of the units;

the date, if any, on and after which the units may be transferable separately;


whether we will apply to have the units traded on a securities exchange or securities quotation system;

anydiscussion of material United States federal income tax consequences;considerations, if applicable; and

how, for United States federal income tax purposes, the purchase price paid for

whether the units is to be allocated among the component securities.

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of debt securities, common stock, preferred stock or other securities. Warrants mayif issued as a separate security will be issued independentlyin fully registered or together with debt securities, common stock, preferred stock or other securities offered byglobal form.


The descriptions of the units in this prospectus and in any prospectus supplement and may be attached to or separate from any such offered securities. Seriesare summaries of warrants may be issued under a separate warrant agreement entered into between us and a bank or trust company, as warrant agent, all as will be set forth in the prospectus supplement relating to the particular issue of warrants. The warrant agent would act solely as our agent in connection with the warrants and would not assume any obligation or relationship of agency or trust for or with any holders of warrants or beneficial owners of warrants.

You should refer to thematerial provisions of the warrant agreementapplicable agreements. These descriptions do not restate those agreements in their entirety and may not contain all the information that you may find useful. We urge you to read the applicable agreements because they, and not the summaries, define your rights as holders of the units. For more information, please review the forms of the relevant agreements, which will be filed with the Securities and Exchange Commission in connection withSEC promptly after the offering of warrants forunits and will be available as described in the complete terms of the warrant agreement.

Prior to the exercise of any warrants, holders of such warrants will not have any rights of holders of the securities purchasable upon such exercise, including the right to receive payments of dividends, or the right to vote such underlying securities.

sections titled “Where You Can Find More Information” and “Information Incorporated by Reference.”        


USE OF PROCEEDS

Unless

Except as may be stated in the applicable prospectus supplement, states otherwise, we expectintend to use the net proceeds we receive from any sales of the sale of our securities by us under this prospectus and any accompanying prospectus supplement for general corporate purposes, including, but not limited to,which may include, among other things:

capital expenditures associated with our rental fleet;
potential future acquisitions of companiescompanies;
reduction or assets, repaymentrefinancing of existing indebtednessdebt or other corporate obligations; and for
-28-


additions to our working capital. As of the date of this prospectus, we have not identified as probable any specific material proposed uses of these proceeds.

If, as of the date of any prospectus supplement, we have identified any such uses, we will describe them in the prospectus supplement. The amount of our

-26-


securities offered from time to time pursuant to this prospectus and any prospectus supplement, and the precise amounts and timing of the application of net proceeds from the sale of those securities, will depend upon our funding requirements. If we elect at the time of an issuance of our securities to make different or more specific use of proceeds than described in this prospectus, such use will be described in the prospectus supplement relating to those securities.

RATIO OF EARNINGS TO FIXED CHARGES

If we offer debt securities and/or preference equity securities under this prospectus, then we will, at that time, provide a ratio of earnings to fixed charges and/or ratio of combined fixed charges and preference dividends to earnings, respectively, in the applicable prospectus supplement for such offering.

PLAN OF DISTRIBUTION

We may sell the offered securities covered by this prospectus from timein and outside the United States pursuant to time. Registrationunderwritten public offerings, negotiated transactions, block trades or a combination of the securities covered by this prospectus does not mean, however, that those securities will necessarily be offered or sold.

these methods. We may sell theour securities separately or together:

together (1) through one or more underwriters or dealers, in a public offering and sale by them;

(2) directly to investors;

purchasers, including our affiliates and stockholders, (3) through agents;agents or

(4) through a combination of any of these methods of sale.

We may sellmethods. The prospectus supplement will include the securities from time to time:

in one or more transactions at a fixed price or prices, which may be changed from time to time;

following information:

at market prices prevailing at the times of sale;


at prices related to such prevailing market prices; or

at negotiated prices.

We will describe the method of distribution of the securities and the terms of the offering in offering;


the prospectus supplement.

Anynames of any underwriters or agents;


the name or names of any managing underwriter or underwriters;

the purchase price of the securities;

the estimated net proceeds to us from the sale of the securities;

any delayed delivery arrangements;

any underwriting discounts, commissions and other items constituting underwriters' compensation;

any discounts or concessions allowed or re-allowedreallowed or paid to dealers may be changed from timedealers; and

any commissions paid to time.

agents.


-29-


Sale Through Underwriters or Dealers

If underwriters are used in the sale of any securities,or a firm commitment basis, the underwriters will acquire the securities will be acquired by the underwriters for their own account andfor resale to the public. The underwriters may also be resoldengaged to sell our securities on a best efforts basis. The underwriters may resell the securities from time to time in one or more transactions, described above. Theincluding negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities may be either offered to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Generally,Unless we inform you otherwise in the underwriters’prospectus supplement and except as described below, the obligations of the underwriters to purchase the securities will be subject to conditions

-27-


precedent and thecertain conditions. The underwriters will be obligatedmay change from time to purchase all of the securities if they purchasetime any of the securities. We may use underwriters with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, the nature of any such relationship.

We may authorize underwriters, dealers or agents to solicit offers by certain purchasers to purchase the securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. The contracts will be subject only to those conditions set forth in the prospectus supplement, and the prospectus supplement will set forth any commissions we pay for solicitation of these contracts.

We may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and will be identified in the applicable prospectus supplement or in a post-effective amendment.

Underwriters, dealers and agents may be entitled to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments made by the underwriters, dealers or agents, under agreements between us and the underwriters, dealers and agents.

We may grant underwriters who participate in the distribution of securities an option to purchase additional securities to cover over-allotments, if any, in connection with the distribution.

Underwriters, dealers or agents may receive compensation in the form of discounts, concessions or commissions from us or our purchasers, as their agents in connection with the sale of securities. These underwriters, dealers or agents may be considered to be underwriters under the Securities Act of 1933. As a result, discounts, commissions or profits on resale received by the underwriters, dealers or agents may be treated as underwriting discounts and commissions. The prospectus supplement will identify any such underwriter, dealer or agent and describe any compensation received by them from us. Any initial public offering price and any discounts or concessions allowed or re-allowed or paid to dealers may be changed from time to time.

Unless otherwise specified indealers.


During and after an offering through underwriters, the related prospectus supplement, all securities we offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do sopurchase and may discontinue any market making at any time without notice. Any common stock sold pursuant to a prospectus supplement will be listed for trading on the New York Stock Exchange

-28-


or other principal market for our common stock. We may apply to list any series of debt securities, preferred stock, depositary shares, rights, units or warrants on an exchange, but we are not obligated to do so. Therefore, there may not be liquidity or a trading market for any series of securities.

Any underwriter may engage in over-allotment transactions, stabilizing transactions, short-covering transactions and penalty bids in accordance with Regulation M under the Securities Exchange Act of 1934. Over-allotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases ofsell the securities in the open market after the distribution is completedmarket. These transactions may include overallotment and stabilizing transactions and purchases to cover syndicate short positions. Penalty bids permitpositions created in connection with the offering. The underwriters may also impose a penalty bid, which means that selling concessions allowed to reclaim a selling concession from a dealer whensyndicate members or other broker-dealers for the offered securities originally sold for their account may be reclaimed by the dealersyndicate if the offered securities are purchasedrepurchased by the syndicate in astabilizing or covering transaction to cover short positions. Thosetransactions. These activities may causestabilize, maintain or otherwise affect the market price of the offered securities, towhich may be higher than it wouldthe price that might otherwise be.prevail in the open market. If commenced, the underwriters may discontinue any of thethese activities at any time. We make no representation or prediction


If dealers are used, we will sell the securities to them as principals. The dealers may then resell the securities to the directionpublic at varying prices determined by the dealers at the time of resale. The dealers participating in any sale of the securities may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will include in the prospectus supplement the names of the dealers and the terms of the transaction.

At-the-Market Offerings

    Underwriters or magnitudeagents could make sales in privately negotiated transactions and/or any other method permitted by law, including sales deemed to be an “at-the-market” offering as defined in Rule 415 under the Securities Act, which includes sales made directly on or through the NYSE, the existing trading market for our common stock, or sales made to or through a market maker other than on an exchange.

    To the extent that we make sales through one or more underwriters or agents in “at-the-market” offerings, we will do so pursuant to the terms of a sales agency financing agreement or other “at-the-market” offering arrangement with such underwriters or agents. If we engage in at-the-market sales pursuant to any such agreement, we will issue and sell securities through one or more underwriters or agents, which may act on an agency basis or on a principal basis. During the term of any effectsuch agreement, we may sell securities on a daily basis in exchange transactions or otherwise as we agree with the underwriters or agents. The agreement will provide that any securities sold will be sold at prices related to the then prevailing market prices for such
-30-


securities. Therefore, exact figures regarding proceeds that will be raised or commissions to be paid cannot be determined at this time. Pursuant to the terms of the agreement, we also may agree to sell, and the relevant underwriters or agents may agree to solicit offers to purchase, blocks of securities. The terms of each such agreement will be set forth in more detail in the applicable prospectus supplement and any related free writing prospectus. In the event that any underwriter or agent acts as principal, or any broker-dealer acts as underwriter, it may engage in certain transactions may have onthat stabilize, maintain, or otherwise affect the price of the securities. For a descriptionAny such activities will be described in the prospectus supplement or any related free writing prospectus relating to the transaction.

Direct Sales and Sales Through Agents

We may sell the securities directly. In this case, no underwriters or agents would be involved. We may also sell the securities through agents we designate from time to time. In the prospectus supplement, we will name any agent involved in the offer or sale of these activities, see the information underoffered securities, and we will describe any commissions payable by us to the heading “Underwriting”agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or “Planothers who may be deemed to be underwriters within the meaning of Distribution”the Securities Act with respect to any sale of those securities. We will describe the terms of any such sales in the prospectus supplement.

Remarketing Arrangements

Offered securities may also be offered and sold, if so indicated in the applicable prospectus supplement.

Underwriters, broker-dealerssupplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents who may become involvedfor us. Any remarketing firm will be identified and the terms of its agreements, if any, with us and its compensation will be described in the saleapplicable prospectus supplement. Remarketing firms may be deemed to be underwriters, as that term is defined in the Securities Act, in connection with the securities remarketed.


Delayed Delivery Contracts

If we so indicate in the prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the common stockpublic offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement. The prospectus supplement will describe the commission payable for solicitation of those contracts.

-31-


General Information

We may have agreements with the agents, dealers, underwriters and remarketing firms to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers, underwriters or remarketing firms may be required to make. Agents, dealers, underwriters and remarketing firms may be customers of, engage in transactions with, andor perform other services for us in the ordinary course of their business for which they receive compensation.

businesses.


LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, Jones & Keller, P.C., Denver, Colorado will provide opinions regarding the authorization and validity of the securities. Jones & Keller, P.C. may also provide opinions regarding certain other matters. Any underwriters will also be advised about legal matters by their own counsel, which will be named in the prospectus supplement.



EXPERTS

Our 2020 consolidated financial statements appearing in our Annual Report on Form 10-K for the year ended December 31, 2020, have been audited by Moss Adams LLP, an independent registered public accounting firm, as stated in their report included therein, which is incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

The consolidated financial statements as of December 31, 2011 and 20102019 and for each of the two years in the periodyear then ended December 31, 2011 and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2011 incorporated by reference in this Prospectus and in the Registration Statement have been so incorporated in reliance on the reportsreport of BDO USA, LLP, an independent registered public accounting firm, incorporated herein by reference, given upon the authority of such firm as experts in auditing and accounting.

The financial statements for the year ended December 31, 2009 incorporated by reference into this Prospectus and in the Registration Statement by reference from our Annual Report on Form 10-K have been audited by Hein & Associates LLP, our former independent registered public accounting firm, given upon the authority of such firm as experts in auditing and accounting.

-29-




TRANSFER AGENT AND REGISTRAR

Our Transfer Agent and Registrar is Computershare Trust Company, Inc., 350 Indiana Street,8742 Lucent Blvd., Suite 800, Golden,225, Highlands Ranch, Colorado 80401.

80129.

INCORPORATION OF CERTAIN





WHERE YOU CAN FIND MORE INFORMATION BY REFERENCE
-

Where You Can Find More Information32

We file annual, quarterly and current reports, proxy statements and other information with the Commission. You may read and copy any reports, statements or other information we file with the Commission at the Commission’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. Please call the Commission at 1-800-SEC-0330 for further information on the operation of the Public Reference Room. Our Commission filings are also available to the public from commercial document retrieval services and at the Internet site maintained by the Commission atwww.sec.gov.-




We have filed with the CommissionSEC a registration statement on Form S-3 relating tounder the Securities Act covering the securities coveredoffered by this prospectus. This prospectus does not contain all of the information that you can find in that registration statement and its exhibits. Certain items are omitted from this prospectus in accordance with the rules and regulations of the SEC. For further information with respect to us and the securities offered by this prospectus, reference is made to the registration statement and the exhibits filed with the registration statement. Statements contained in this prospectus as to the contents of any prospectus supplement. This prospectuscontract or other document referred to are not necessarily complete and in each instance such statement is aqualified by reference to each such contract or document filed with or incorporated by reference as part of the registration statementstatement. We are required to file annual and quarterly reports and other information with the SEC. The SEC maintains an Internet site that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC. The address of the site is http://www.sec.gov.

You can also find our SEC filings through the investors relations section of our website at www.ngsgi.com. The information contained on our website or any other website is not incorporated by reference into this prospectus and does not contain all the information in the registration statement. Whenever a reference is made in this prospectus or any prospectus supplement to a contract or other document, the reference is only a summary and you should refer to the exhibits that areconstitute a part of the registration statement for a copy of the contract or other document. You may review a copy of the registration statement at the Commission’s public reference room in Washington, D.C., as well as through the Commission’s Internet site.

this prospectus.


INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The CommissionSEC allows us to “incorporate by reference” into this prospectus the information that we file with it,them, which means that we can disclose important information to you by referring you to those documents.documents previously filed with the SEC. The information incorporated by reference is considereddeemed to be part of this prospectus except for any information that is superseded by information included directly in this prospectus, and the information that we file later with the CommissionSEC will automatically update and supersede suchthis information. Any statement contained in this prospectus or a document incorporated by reference in this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document that is incorporated by reference in this prospectus modifies or superseded the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus. You should not assume that the information in this prospectus is current as of the date other than the date on the cover page of this prospectus.

The following documents filed with the CommissionSEC are hereby incorporated by reference into this prospectus:

A.

A.our Annual Report on Form 10-K for the Fiscal Year Ended December 31, 2011;

B.our Quarterly Report on Form 10-Q for the quarters ended March 31, 2012 and June 30, 2012;

C.our Current Reports on Form 8-K filed on January 9, 2012, March 8, 2012, May 10, 2012, June 15, 2012, August 7, 2012 and October 11, 2012;

D.the description of our Common Stock, par value $.01 per share, set forth in our Registration Statement on Form 8-A filed on July 17, 2002, including any amendment or report filed for the purpose of updating such description;

-30-


E.our Definitive Proxy Statement on Schedule 14A filed on April 27, 2012; and

F.all documents filed by us with the Commission pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended, subsequent to the date of this Registration Statement shall be deemed to be incorporated herein by reference and to be a part of this Registration Statement from the date of the filing of such documents until such time as there shall have been filed a post-effective amendment that indicates that all securities offered hereby have been sold or that deregisters all securities remaining unsold at the time of such amendment.

Our Internet address iswww.ngsgi.com. We make available free of charge, through the investor relations section of our website, Annual Reports on Form 10-K for the Fiscal Year Ended December 31, 2020, filed on March 31, 2021;


B.our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021 (filed on May 14, 2021), June 30, 2021 (filed on August 16, 2021) and September 30, 2021 (filed on November 12, 2021);
C.our Current Reports on Form 8-K filed on February 10, 2021; March 24, 2021; March 30, 2021; April 5, 2021; May 11, 2021; May 13, 2021; June 22, 2021; August
-33-


11 2021 and amendments to those reportsOctober 2, 2021 (excluding any portion of such documents which are furnished and not filed with the SEC); and

D.the description of our Common Stock, par value $0.01 per share, set forth in our Registration Statement on Form 8-A filed on July 17, 2002, including any amendment or furnishedreport filed for the purpose of updating such description.

We are also incorporating by reference into this prospectus any additional documents that we may file with the SEC pursuant to SectionSections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 as soon as reasonably practicable(excluding any information furnished and not filed with the SEC) after we electronically file such material with, or furnish it to, the securities and Exchange Commission. The informationdate on which appears on this web site is not part of this prospectus.

This prospectus is part of athe registration statement that weincludes this prospectus was initially filed with the Commission. Upon written or oral request,SEC (including all such documents that we may file with the SEC after the date of the initial registration statement and prior to the effectiveness of the registration statement) and until all offerings under this registration statement are terminated shall be deemed to be incorporated in this prospectus by reference and to be a part hereof from the date of filing of such documents.


We will provide without charge, to each person, including any beneficial owners of our securities,holder, to whom a copy of this prospectus is delivered, at no cost, upon written or oral request, a copy of any or all of the information that has been incorporated by reference in thisthe prospectus (other than exhibitsbut not delivered with the prospectus. You should direct any requests for documents to such documents, unless the exhibits are specificallyfollowing address or telephone number:

Natural Gas Services Group, Inc.
Attention: Investor Relations
404 Veterans Airpark Lane, Suite 300
Midland, Texas 79705
(432) 262-2700

    You should rely only on the information contained or incorporated by reference into this prospectus or in such documents). Your requests for copiesany prospectus supplement.  We have not authorized anyone to provide you with different information.  If anyone provides you with different or inconsistent information, you should be directednot rely on it.  We are not making an offer to sell, or soliciting an offer to buy, securities in any jurisdiction where the Investor Relations, 508 West Wall Street, Suite 550, Midland, Texas 79701; telephone (432) 262-2700.

offer and sale is not permitted.


DISCLOSURE OF COMMISSIONSEC POSITION ON INDEMNIFICATION

FOR SECURITIES ACT LIABILITIES

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of registrant pursuant to the above, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable.

-31-

-34-



INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14.OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION, ESTIMATED


The following is a statement of the estimated costs and expenses, other than underwriting compensation, incurred or expected to be incurred by us in connection with the issuance and distribution of an assumed amount of $150,000,000 of securities being registered pursuant to this registration statement. The assumed amount has been used to demonstrate the costs and expenses of an offering of the entire assumed amount of securities being registered and does not represent an estimate of the amount of securities that may be offered because such amount is unknown at this time. All of the amounts shown are estimates except for the SEC registration fee. The amounts also assume no listing of any additional class of securities on the New York Stock Exchange that would require the payment of an additional listing fee.

Securities and Exchange Commission Fee

  $20,460  

Filing & Printing Expense

  $5,000

Legal Fees

  $6,500

Accountants’ Fees

  $3,500

Miscellaneous Fees and Expenses

  $1,540
  

 

 

 

Total

  $37,000
  

 

 

 


Securities and Exchange Commission Fee $13,905
FINRA Filing Fees$*
Filing & Printing Expense $*
Legal Fees $*
Accountants’ Fees $*
Printing Expenses*
Trustee’s Fees and Expenses*
Transfer Agent Expenses*
Miscellaneous Fees and Expenses $*
    
Total $*
* BecauseEstimated fees and expenses are not presently known. The foregoing sets forth the general categories of fees and expenses (other than underwriting discounts and commissions) that we anticipate we might incur in connection with an indeterminate amountoffering of securities is covered byunder this Registration Statement,registration statement. An estimate of the aggregate fees and expenses in connection with the issuance and distribution of the securities are not currently determinable. The expenses set forth above relate solely tobeing offered will be included in the preparation and filing of this Registration Statement.

applicable prospectus supplement.

ITEM 15.INDEMNIFICATION OF DIRECTORS AND OFFICERS


Section 7-109-102 of the Colorado Business Corporation Act permits a Colorado corporation to indemnify any director against liability if such person acted in good faith and, in the case of conduct in an official capacity with the corporation, that the director’s conduct was in the corporation’s best interests and, in all other cases, that the director’s conduct was at least not
II-1


opposed to the best interests of the corporation or, with regard to criminal proceedings, the director had no reasonable cause to believe the director’s conduct was unlawful.


Section 7-109-103 of the Colorado Business Corporation Act provides that, unless limited by its articles of incorporation, a Colorado corporation shall indemnify a person who was wholly successful, on the merits or otherwise, in the defense of any proceeding to which the person was a party because the person is or was a director, against reasonable expenses incurred by him or her in connection with the proceeding.

II-1



Section 3 of Article IX of our articlesArticles of incorporationIncorporation, as amended, provides that we shall indemnify, to the maximum extent permitted by law in effect from time to time, any person who is or was a director, officer, agent, fiduciary or employee of ours against any claim, liability or expense arising against or incurred by such person made party to a proceeding because such person is or was a director, officer, agent, fiduciary or employee of ours or because such person is or was serving another entity as a director, officer, partner trustee, employee, fiduciary or agent at our request. We further have the authority to the maximum extent permitted by law to purchase and maintain insurance providing such indemnification.

Article VI of our bylaws provides for the indemnification of certain persons.


Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that in the opinion of the Securities and Exchange CommissionSEC such indemnification is against public policy as expressed in the Securities Act of 1933 and is, therefore, unenforceable.


At present, there is no pending litigation or proceeding involving any of our directors, officers, employees or agents where indemnification will be required or permitted. Insofar as indemnification for liabilities arising under the Securities Act of 1933 Act may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act of 1933 Act and is, therefore, unenforceable.


II-2




ITEM 16.EXHIBITS

Exhibit No.

ITEM 16.
EXHIBITS

Description

Exhibit No.Description
1.1Form of Underwriting Agreement†
Agreement †
3.1Articles of Incorporation, as amended (Incorporated by reference to Exhibit 3.1 of Form 10-QSB filed and dated November 10, 2004)
3.2
3.2Bylaws, as amended (Incorporated by reference to Exhibit 3.43.1 of the Registrant's Current Report on Form 8-K, filed with the SEC on February 10, 2021)
4.1Description of Securities (Incorporated by reference to the Registrant’s Registration Statement on Form SB-2, No. 333-88314)
4.1Form of Senior Indenture (Incorporated by reference to Exhibit 4.1 of the Registrant’s Registration Statement on Form S-3, No. 333-161346,8-A, filed with the SEC on August 14, 2009)
October 27, 2008.)
4.2Form of Senior Indenture*
4.3Form of Senior Note†
4.4
4.3Form of Subordinated Indenture (Incorporated by reference to Exhibit 4.1 of the Registrant’s Registration Statement on Form S-3, No. 333-161346, filed with the SEC on August 14, 2009)Indenture*
4.5
4.4Form of Subordinated Note†
4.6
4.5Form of Deposit Agreement, including Form of Depositary Share†
4.7
4.6Form of Warrant Agreement, including Form of Warrant Certificate†
4.8
4.7Form of Unit Agreement†
4.9
4.8Form of Preferred Stock Certificate†
4.10
4.9Form of Certificate of Designation with respect to Preferred Stock†
4.11
4.10Rights Agreement, including Form of Rights Certificate†
5.1 Opinion of Jones & Keller, P.C. regarding the legality of the common stock being registered*
*
23.1

Consent of Moss Adams, LLP*
23.2

Consent of BDO USA*
23.2Consent of Hein & AssociatesUSA, LLP*
23.3 Consent of Jones & Keller, P.C. (included(previously included in Exhibit 5.1)
24.1 Power of Attorney (included(previously included on the signature page hereof)
page)
25.1 Statement of Eligibility on Form T-1 under the Trust Indenture Act of 1939, as amended (to be incorporated herein by reference from a subsequent filing in accordance with section 304(b)(2) of the Trust Indenture Act of 1939.)

*Filed herewith.
If applicable, to be subsequently filed by amendment or as an exhibit to a Current Report on Form 8-K and incorporated herein by reference.








II-3



ITEM 17.UNDERTAKINGS


The undersigned registrant hereby undertakes:


(1)           To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

i.To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;
ii.To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and
iii.To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;


i.To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;
ii.To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and
iii.To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that

(A)the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the registration statement is on Form S-8, and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement; and

(B)the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the registration statement is on Form S-3 or Form F-3 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement or is contained in a form of prospectus filed pursuant to Rule 424(b) that is a part of the registration statement.

(C)

(A)the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the registration statement is on Form S-8, and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement; and

(B)the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the registration statement is on Form S-3 or Form F-3 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement or is contained in a form of prospectus filed pursuant to Rule 424(b) that is a part of the registration statement.

(C)Provided further, however, that paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the registration statement is for an offering of asset-backed securities on Form S-1 or Form S-3, and the information required to be included in a post-effective amendment is provided pursuant to Item 1100(c) of Regulation AB.
Provided further, however, that paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the registration statement is for an offering of asset-backed securities on Form S-1 or Form S-3, and the information required to be included in a post-effective amendment is provided pursuant to Item 1100(c) of Regulation AB.

II-4




(2)           That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)           To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4)


(6) That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

i.Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and
ii.

i.Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and
ii.Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(7) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:


i.Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;
ii.Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;
II-5


i.Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;
ii.Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;
iii.The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and
iv.Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.


iii.The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and
iv.Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.


The undersigned registrant hereby undertakes to deliver or cause to be delivered with the prospectus, to each person to whom the prospectus is sent or given, the latest annual report to security holders that is incorporated by reference in the prospectus and furnished pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the Securities Exchange Act of 1934; and, where interim financial information required to be presented by Article 3 of Regulation S-X are not set forth in the prospectus, to deliver, or cause to be delivered to each person to whom the prospectus is sent or given, the latest quarterly report that is specifically incorporated by reference in the prospectus to provide such interim financial information.


The undersigned registrant hereby undertakes that:


(1)           For purposes of determining any liability under the Securities Act of 1933, the information omitted from the form of prospectus filed as part of this registration statement in reliance upon Rule 430A and contained in a form of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act of 1933 shall be deemed to be part of this registration statement as of the time it was declared effective.

(2)   For the purpose of determining any liability under the Securities Act of 1933, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.


Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities

II-6


(other (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such

II-6


indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.


II-7



SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statementRegistration Statement to be signed on its behalf by the undersigned, thereunto duly authorized in the City of Midland, State of Texas, on October 31, 2012.

November 15, 2021.

NATURAL GAS SERVICES GROUP, INC.
By: 
By:/s/ Stephen C. Taylor
 

Stephen C. Taylor

Chief Executive Officer

(Principal Executive Officer)
By: /s/ G. Larry Lawrence

G. Larry Lawrence

Principal Accounting Officer

KNOW ALL MEN BY THESE PRESENTS, that the undersigned officers or directors of the registrant, by virtue of their signatures to this registration statement appearing below, hereby constitute and appoint Stephen C. Taylor and G. Larry Lawrence, attorneys-in-fact in their names, place, and stead to execute any and all amendments to this registration statement in the capacities set forth opposite their names and hereby ratify all that said attorneys-in-fact may do by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statementRegistration Statement has been signed by the following persons in the capacities and on the date indicated.

Name and SignatureTitleDate

Signature

Title

Date

/s/ Stephen C. Taylor

Stephen C. Taylor

Director

October 31, 2012

/s/ David L. Bradshaw

David L. Bradshaw

Director,

October 31, 2012
Chief Executive Officer, and President (Principal Executive Officer)November 15, 2021

/s/ John W. Chisholm

John W. Chisholm

Director

October 31, 2012

II-8


/s/ Micah C. Foster
Micah C. Foster

/s/ Charles G. Curtis

Charles G. Curtis

Chief Financial Officer (Principal Financial Officer and Principal Accounting Officer)

Director

October 31, 2012November 15, 2021

/s/ William F. Hughes, Jr.

William F. Hughes, Jr.

David L. Bradshaw
David L. Bradshaw

Director

October 31, 2012November 15, 2021

/s/ Kenneth V. Huseman

Kenneth V. Huseman

John W. Chisholm
John W. Chisholm

Director

October 31, 2012November 15, 2021

II-9


EXHIBIT INDEX

Exhibit No.

/s/ Leslie A. Beyer
Leslie A. Beyer

Description

Director
November 15, 2021
1.1
/s/ Nigel J. Jenvey
Nigel J. Jenvey
DirectorNovember 15, 2021

II-8


SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized in the City of Midland, State of Texas, on November 15, 2021.

 NGSG PROPERTIES, LLC
By:/s/ Stephen C. Taylor
Stephen C. Taylor
Chief Executive Officer
KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Stephen C. Taylor and Micah C. Foster, and each of them acting individually, jointly and severally, as his true and lawful attorneys-in-fact and agents, with full power of each to act alone, with full powers of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any and all amendments to this Registration Statement on Form S-3 (including post-effective amendments), and to sign any registration statement for the same offering covered by this Registration Statement that is to be effective upon filing pursuant to Rule 462(b) promulgated under the Securities Act, and all post-effective amendments thereto, and to file the same, with all exhibits thereto and all documents in connection therewith, with the SEC, granting unto said attorneys-in-fact and agents, with full power of each to act alone, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully for all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or his or their substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the date indicated.
Name and SignatureTitleDate
/s/ Stephen C. TaylorChief Executive Officer, and PresidentNovember 15, 2021
Stephen C. Taylor(Principal Executive Officer), Manager

/s/ Micah C. Foster

Chief Financial Officer (Principal Financial
November 15, 2021
Micah C. FosterOfficer and Principal Accounting Officer)

II-9


EXHIBIT INDEX

Exhibit No.Description
Form of Underwriting Agreement†Agreement †
3.1Articles of Incorporation, as amended (Incorporated by reference to Exhibit 3.1 of Form 10-QSB filed and dated November 10, 2004)
3.2Bylaws, as amended (Incorporated by reference to Exhibit 3.43.1 of the Registrant's Current Report on Form 8-K, filed with the SEC on February 10, 2021)
Description of Securities (Incorporated by reference to the Registrant’s Registration Statement on Form SB-2, No. 333-88314)
4.1Form of Senior Indenture (Incorporated by reference to Exhibit 4.1 of the Registrant’s Registration Statement on Form S-3, No. 333-161346,8-A, filed with the SEC on August 14, 2009)October 27, 2008.)
Form of Senior Indenture*
4.24.3Form of Senior Note†
4.3Form of Subordinated Indenture (Incorporated by reference to Exhibit 4.1 of the Registrant’s Registration Statement on Form S-3, No. 333-161346, filed with the SEC on August 14, 2009)Indenture*
4.5
4.4Form of Subordinated Note†
4.6
4.5Form of Deposit Agreement, including Form of Depositary Share†
4.7
4.6Form of Warrant Agreement, including Form of Warrant Certificate†
4.8
4.7Form of Unit Agreement†
4.9
4.8Form of Preferred Stock Certificate†
4.10
4.9Form of Certificate of Designation with respect to Preferred Stock†
4.11
4.10Rights Agreement, including Form of Rights Certificate†
 Opinion of Jones & Keller, P.C. regarding the legality of the common stock being registered*

Consent of Moss Adams, LLP*
23.1

Consent of BDO USA*
23.2Consent of Hein & AssociatesUSA, LLP*
23.3 Consent of Jones & Keller, P.C. (included(previously included in Exhibit 5.1)
24.1 Power of Attorney (included(previously included on the signature page hereof)
page)
25.1 Statement of Eligibility on Form T-1 under the Trust Indenture Act of 1939, as amended (to be incorporated herein by reference from a subsequent filing in accordance with section 304(b)(2) of the Trust Indenture Act of 1939.)


*Filed herewith.
If applicable, to be subsequently filed by amendment or as an exhibit to a Current Report on Form 8-K and incorporated herein by reference.



II-10