Exhibit 99.1

Pegasystems Announces Financial Results for Fourth Quarter and Full Year 2015

GAAP License and Cloud Revenue up 23% While Achieving Record Backlog

CAMBRIDGE, Mass. – February 25, 2016 – Pegasystems Inc. (NASDAQ: PEGA), the software company empowering the world’s leading enterprises with strategic business applications, today announced results for its fourth quarter and full year ended December 31, 2015.

“Q4 was a very strong quarter capping off a record year for Pega that included record revenue, backlog, and bookings” said Alan Trefler, Founder and CEO, Pegasystems. “For the full year, total GAAP revenue was $683 million, an increase of 16% over 2014. We grew GAAP license and cloud revenue 23% over the full year 2014 while increasing backlog 15% over the prior year-end.”

“We continue to be very positive about how our value proposition is being received and about our long-term growth opportunities,” continued Mr. Trefler, “We are extremely well positioned in the market as the pace of change for organizations continues to increase. We believe the need for strategic applications to help them manage and leverage that change for competitive advantage – while gaining efficiencies and connecting their businesses from back office to front office – will continue to be in demand.”

SELECTED GAAP & NON-GAAP RESULTS (1)

Cash: Total cash, cash equivalents, and marketable securities at December 31, 2015 was $219.1 million, up 4% from December 31, 2014.

Cash generated from operations for the full year 2015 was $62.5 million. Free Cash Flow, which we define as operating cash flow less Cap Ex, was $51.5 million for 2015.

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License and Cloud Backlog: The Company computes license and cloud backlog by adding billed deferred license and cloud revenue and off-balance sheet license and cloud commitments, which is business that is contracted, unbilled, and not recorded on the Company’s balance sheet.

License and Cloud Backlog (1)

Business Outlook: As of February 25, 2016, Pegasystems is initiating revenue and EPS guidance for the full year 2016 as follows:

Full Year 2016 Revenue: GAAP and non-GAAP revenue for the full year 2016 is projected to be approximately $780 million.

Full Year 2016 Earnings Per Share: GAAP diluted earnings per share for the full year 2016 is expected to be approximately $0.50. Non-GAAP diluted earnings per share for the full year 2016 is expected to be approximately $0.95.

See the reconciliation of our GAAP diluted EPS guidance to non-GAAP diluted EPS guidance for the full year of 2016 at the end of this release.

Quarterly Conference Call

Pegasystems will host a conference call and audio-only Webcast associated with this announcement at 5:00 p.m. EST today. A live audio webcast of the conference call, together with detailed financial information, can be accessed through the Company’s Website at www.pega.com/about/investors. Dial-in information is as follows: 1-877-407-3982 (domestic) or 1-201-493-6780 (international). To listen to the Webcast, log onto www.pega.com at least five minutes prior to the event’s broadcast and click on the Webcast icon in the Investors section. A replay of the call will also be available on www.pega.com by clicking the Earnings Calls link in the Investors section.

Discussion of Non-GAAP Financial Measures:

To supplement financial results presented in accordance with Generally Accepted Accounting Principles in the U.S. (“GAAP”), the Company provides non-GAAP measures, including in this release. Pegasystems’ management utilizes a number of different financial measures, both GAAP and non-GAAP, in analyzing and assessing the overall performance of the business, for making operating decisions, and for forecasting and planning for future periods. The Company’s annual financial plan is prepared both on a GAAP and non-GAAP basis, and both are approved by our board of directors. In addition and as a consequence of the importance of these measures in managing the business, the Company uses non-GAAP measures and financial performance results in the evaluation process to establish management’s compensation.

The non-GAAP measures exclude the effects of certain business combination accounting entries, stock-based compensation expense, amortization of acquired intangibles, acquisition-related and restructuring expenses, and certain other adjustments. The Company believes that these non-GAAP measures are helpful in understanding its past financial performance and its anticipated future results. These non-GAAP financial measures are not meant to be considered in isolation or as a substitute for comparable GAAP measures and should be read only in conjunction with the Company’s consolidated financial statements prepared in accordance with GAAP. A reconciliation of the Company’s GAAP to non-GAAP measures is included in the financial schedules at the end of this release.

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Forward-Looking Statements

“Safe harbor” statement under the Private Securities Litigation Reform Act of 1995: Certain statements contained in this press release may be construed as “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995, including our guidance regarding 2016 GAAP and non-GAAP revenue and diluted earnings per share. The words “expect,” “anticipate,” “intend,” “plan,” “believe,” “could,” “estimate,” “may,” “target,” “strategy,” “is intended to,” “project,” “guidance”, or variations of such words and similar expressions, among others, identify forward-looking statements, which speak only as of the date the statement was made. These statements are based on current expectations and assumptions and involve various risks and uncertainties, which could cause the Company’s actual results to differ from those expressed in such forward-looking statements. These risks and uncertainties include, among others, variation in demand for our products and services and the difficulty in predicting the completion of product acceptance and other factors affecting the timing of our license revenue recognition; the ongoing consolidation in the financial services, insurance, healthcare, and communications markets; reliance on third party relationships; the potential loss of vendor specific objective evidence for our time and materials professional services arrangements; the inherent risks associated with international operations and the continued weakness in international economies; foreign currency exchange rates; the financial impact of the Company’s past acquisitions and any future acquisitions; the potential legal and financial liabilities and reputation damage due to cyber-attacks and security breaches, and management of the Company’s growth. Further information regarding these and other factors which could cause the Company’s actual results to differ materially from any forward-looking statements contained in this press release is contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 and other recent filings with the Securities and Exchange Commission. These documents are available on the Company’s website at http://www.pega.com/about/investors. The forward-looking statements contained in this press release represent the Company’s views as of February 25, 2016. Investors are cautioned not to place undue reliance on such forward-looking statements and there are no assurances that the matters contained in such statements will be achieved. Although subsequent events may cause the Company’s view to change, except as required by applicable law, the Company does not undertake and specifically disclaims any obligation to publicly update or revise these forward-looking statements whether as the result of new information, future events or otherwise. The statements should therefore not be relied upon as representing the Company’s view as of any date subsequent to February 25, 2016.

About Pegasystems

Pegasystems (NASDAQ: PEGA) develops strategic applications for marketing, sales, service, and operations. Pega’s applications streamline critical business operations, connect enterprises to their customers seamlessly in real-time across channels, and adapt to meet rapidly changing requirements. Pega’s Global 3000 customers include many of the world’s most sophisticated and successful enterprises. Pega’s applications, available in the cloud or on-premises, are built on its unified Pega 7 platform, which uses visual tools to easily extend and change applications to meet clients’ strategic business needs. Pega’s clients report that Pega gives them the fastest time to value, extremely rapid deployment, efficient re-use and global scale. For more information, please visit us at www.pega.com.

Press Contacts:

Lisa Pintchman

Pegasystems Inc.

lisa.pintchman@pega.com

(617) 866-6022

Twitter: @pega

Investor Contact:

Sheila Ennis

ICR for Pegasystems

PegaInvestorRelations@pega.com

617-866-6077

All trademarks are the property of their respective owners.

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Pegasystems Inc.

Condensed Consolidated Statements of Operations

($ in thousands, except per share amounts)

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PEGASYSTEMS INC.

RECONCILIATION OF SELECTED GAAP MEASURES TO NON-GAAP MEASURES (1)

($ in thousands, except per share amounts)

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PEGASYSTEMS INC.

RECONCILIATION OF SELECTED GAAP MEASURES TO NON-GAAP MEASURES (1)

($ in thousands, except per share amounts)

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PEGASYSTEMS INC.

FOOTNOTES FOR RECONCILIATON OF

SELECTED GAAP MEASURES TO NON-GAAP MEASURES

Revenue: Business combination accounting rules require that we determine the fair value of the deferred revenue liability for contractual obligations assumed primarily from our acquisition of Antenna Software, Inc. and its subsidiaries (“Antenna”) in October 2013. In post-acquisition reporting periods, we recognize revenue for the fair value of these contracts, when all the revenue recognition criteria are satisfied, instead of the revenue that would have been recognized by Antenna as an independent company. We add back the effect of the deferred revenue fair value adjustment in non-GAAP revenue to reflect the full amount of these revenues to provide a more complete comparison of the revenue guidance to peer companies. No adjustments were made to revenue for 2015.

Amortization of intangible assets: We have excluded the amortization expense of intangible assets from our non-GAAP operating expenses and net earnings measures. Amortization of intangible assets is inconsistent in amount and frequency and is significantly affected by the timing and size of our acquisitions. Investors should note that the use of intangible assets contributed to our revenues earned during the periods presented and will contribute to our future period revenues as well. Amortization of intangible assets will recur in future periods.

Stock-based compensation expenses: We have excluded stock-based compensation expense from our non-GAAP operating expenses and net earnings measures. Although stock-based compensation is a key incentive offered to our employees, and we believe such compensation contributed to the revenues earned during the periods presented and will contribute to the generation of future period revenues, we continue to evaluate our business performance excluding stock-based compensation expense.

Acquisition-related and restructuring expenses: We have excluded the effect of acquisition-related and restructuring expenses from our non-GAAP operating expenses and net earnings measures. We incurred direct and incremental expenses associated primarily with the Antenna and 2014 acquisitions. These acquisition-related expenses were primarily professional fees to affect the acquisitions. We have also incurred restructuring expenses related to the integration of the Antenna acquisition, which we generally would not have otherwise incurred in the periods presented as a part of our continuing operations. Restructuring expenses consist primarily of lease exit costs. We believe it is useful for investors to understand the effects of these items on our total operating expenses.

Other adjustments: We reached an agreement with the former shareholders of Antenna to release a portion of the funds held in escrow as security for their indemnification obligations to us in settlement of the outstanding indemnification claims. The settlement resulted in a benefit to cost of revenue and operating expenses in the first quarter of 2015. In addition, we favorably settled indirect tax liabilities related to the Antenna acquisition, which resulted in a benefit to operating expenses in the first quarter of 2015. In the fourth quarter of 2015, we reduced our estimate of the additional cash consideration payable to selling shareholders of one of the three companies acquired in 2014 based on the achievement of certain performance milestones. We believe the benefits associated with these items are not representative of our ongoing business, and we have excluded the effects of these items from our non-GAAP operating results and net earnings measures.

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The GAAP income tax effects were calculated using an effective tax rate of 40% and 30.7% for the full year 2015 and 2014, respectively. The non-GAAP income tax effects were calculated using an effective non-GAAP tax rate of 35.1% and 31.7% for the full year 2015 and 2014, respectively.

The differences between our GAAP and non-GAAP effective tax rates for 2015 primarily relate to the favorable impact of stock-based compensation expense adjustments on non-GAAP effective tax rates. The differences between our GAAP and non-GAAP effective tax rates for 2014 primarily relate to the impact of higher non-GAAP income subjected to tax in higher tax rate jurisdictions.

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Pegasystems Inc.

Condensed Consolidated Balance Sheets

(in thousands)

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Condensed Consolidated Statements of Cash Flows

(in thousands)

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Historical License and Cloud Backlog

(in thousands)

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FY 2016 Reconciliation of Forward-Looking Guidance

($ in thousands, except per share amounts)

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