Release Details

NEWS
NYSE: NGS
Exhibit 99 

 MIDLAND, Texas August 8, 2013 - Natural Gas Services Group, Inc. (NYSE:NGS), a leading provider of gas compression equipment and services to the natural gas industry, announces its financial results for the three and six months ended June 30, 2013.

Revenue: Total revenue was $20.3 million, a decrease from $24.5 million, or 17%, for the three months ended June 30, 2013, compared to the same period ended June 30, 2012. This decrease is primarily due to a non-recurring sale of units from our rental fleet to a single customer during the three months ended June 30, 2012.  Rental revenues increased 22% in the same year-over-year period and 4% sequentially. Total revenues decreased 16% between the first quarter of 2013 and this current period with all this attributable to compressor sales.
           
Gross Margins: Total gross margin increased 12% from $11.0 million for the three months ended June 30, 2012 to $12.3 million for the same period ended June 30, 2013.  Sequentially, gross margin increased 1% from $12.2 million to $12.3 million. Overall gross margin percentage was 61% for the three months ended June 30, 2013, compared to 45% for the same period ended June 30, 2012. This increase is a combination of a relatively higher mix of higher margin rentals plus higher margins experienced in our sales business.    

Operating Income: Operating income for the three months ended June 30, 2013 was $5.8 million, up 21% from the comparative prior year's level of $4.8 million. This increase was primarily driven by a shift in our product mix and generally higher margins.  Sequentially, operating income decreased 5% to $5.8 million for the three months ended June 30, 2013 from $6.1 million.  This decrease was primarily caused by the lower level of compressor sales, but was also impacted by a slight increase in SG&A quarterly expenses and higher depreciation expense due to rental fleet additions.

Net Income:  Net income for the three months ended June 30, 2013 increased 28% to $3.8 million, when compared to net income of $3.0 million for the same period in 2012.  Net income margins for the three months ended June 30, 2013 increased to 19% from 12% for the three months ended June 30, 2012. This increase was mainly because of the higher predominance of the compressor rentals in this period, generally higher margins in all segments and lower effective tax rate. Net income decreased 4% in sequential quarters from $4.0 million to $3.8 million for the same reasons as noted with operating income.

Earnings per share:  Comparing the three months of 2013 versus 2012, earnings per diluted share improved to 31 cents from 24 cents, or 29%.  Diluted earnings decreased 3% per share, to 31 cents from 32 cents, between sequential quarters.

EBITDA:  EBITDA increased 18% to $10.2 million or 50% of revenue for the three months ended June 30, 2013 versus $8.7 million or 35% of revenue for the same three months ended June 30, 2012. Please see discussion of Non-GAAP measures.

Cash flow: At June 30, 2013, cash and cash equivalents were approximately $29.3 million; working capital was $53.0 million with a total debt level of $847 thousand, all of which was classified as non-current. Positive net cash flow from operating activities was approximately $19.4 million during the first six months of 2013 compared to $20.4 million for the same period in 2012.  The changes in operating cash flow relate exclusively to normal variations in our working capital accounts.

Commenting on first quarter 2013 results, Stephen C. Taylor, President and CEO, said:
"We are very pleased with the growth the Company continues to exhibit.  Our rental business is expanding aggressively and our margins this quarter were very robust at 63% of revenue.  In fact, our rental business shows an even better year-over-year growth rate of 22% than last quarter's comparison.  We were able to increase our compressor fabrication volume to 65 unites this quarter, up from 49 units last quarter.  Compressor sales revenues continue their variability due to the comparison against the large one-time sale of some rental equipment last year, very active first quarter this year and our stated intent to sacrifice some compressor sales revenues in favor of rental fabrication, but they continue on-track with the anticipated revenue level that I mention last quarter of approximately $10 million this year.  Overall, we see the market continuing at a good pace through the balance of the year."

Selected data: The table below shows revenues, percentage of total revenues, gross margin, exclusive of depreciation, and gross margin percentage of each business segment for the three months ended June 30, 2013 and 2012.  Gross margin is the difference between revenue and cost of sales, exclusive of depreciation.

(1) For a reconciliation of gross margin to its most directly comparable financial measure calculated and presented in accordance with GAAP, please read "Non-GAAP Financial Measures" below.

Non GAAP Measures: "EBITDA" reflects net income or loss before interest, taxes, depreciation and amortization.  EBITDA is a measure used by analysts and investors as an indicator of operating cash flow since it excludes the impact of movements in working capital items, non-cash charges and financing costs.  Therefore, EBITDA gives the investor information as to the cash generated from the operations of a business.  However, EBITDA is not a measure of financial performance under accounting principles generally accepted in the United States of America ("GAAP"), and should not be considered a substitute for other financial measures of performance.  EBITDA as calculated by NGS may not be comparable to EBITDA as calculated and reported by other companies. The most comparable GAAP measure to EBITDA is net income. The reconciliation of net income to EBITDA and gross margin is as follows:

"Gross margin" is defined as total revenue less cost of sales (excluding depreciation and amortization expense).  Gross margin is included as a supplemental disclosure because it is a primary measure used by management as it represents the results of revenue and cost of sales (excluding depreciation and amortization expense), which are key operating components.  Depreciation expense is a necessary element of costs and the ability to generate revenue and selling, general and administrative expense is a necessary cost to support operations and required corporate activities.  Management uses this non-GAAP measure as a supplemental measure to other GAAP results to provide a more complete understanding the company's performance.  As an indicator of operating performance, gross margin should not be considered an alternative to, or more meaningful than, net income as determined in accordance with GAAP.  Gross margin may not be comparable to a similarly titled measure of another company because other entities may not calculate gross margin in the same manner.

Cautionary Note Regarding Forward-Looking Statements:

Except for historical information contained herein, the statements in this release are forward-looking and made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.  Forward-looking statements involve known and unknown risks and uncertainties, which may cause NGS's actual results in future periods to differ materially from forecasted results.  Those risks include, among other things, the loss of market share through competition or otherwise; the introduction of competing technologies by other companies; a prolonged, substantial reduction in oil and gas prices which could cause a decline in the demand for NGS's products and services; and new governmental safety, health and environmental regulations which could require NGS to make significant capital expenditures. The forward-looking statements included in this press release are only made as of the date of this press release, and NGS undertakes no obligation to publicly update such forward-looking statements to reflect subsequent events or circumstances. A discussion of these factors is included in the Company's most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission.

Conference Call Details:

Teleconference: Thursday, August 8, 2013 at 10:00 a.m. Central (11:00 a.m. Eastern).  Live via phone by dialing 800-624-7038, pass code "Natural Gas Services".   All attendees and participants to the conference call should arrange to call in at least 5 minutes prior to the start time.

Live Webcast: The webcast will be available in listen only mode via our website www.ngsgi.com, investor relations section.

Webcast Reply: For those unable to attend or participate, a replay of the conference call will be available within 24 hours on the NGS website at www.ngsgi.com.

Stephen C. Taylor, President and CEO of Natural Gas Services Group, Inc. will be leading the call and discussing the financial results for the three months ended June 30, 2013.

About Natural Gas Services Group, Inc. (NGS):
NGS is a leading provider of small to medium horsepower, wellhead compression equipment to the natural gas industry with a primary focus on the non-conventional gas industry, i.e., coal bed methane, gas shale and tight gas. The Company manufactures, fabricates, rents and maintains natural gas compressors that enhance the production of natural gas wells. The Company also designs and sells custom fabricated natural gas compressors to particular customer specifications and sells flare systems for gas plant and production facilities. NGS is headquartered in Midland, Texas with manufacturing facilities located in Tulsa, Oklahoma, Lewiston, Michigan and Midland, Texas and service facilities located in major gas producing basins in the U.S.