Alan Olsen, CPA, MBA (Tax)
Managing Partner

Alan is managing partner at Greenstein, Rogoff, Olsen & Co., LLP, a leading CPA firm in the San Francisco Bay Area. His firm was recently (October 2007) recognized by INSIDE Public Accounting as one of the Best-Managed CPA firms in the USA.  Alan has more than 23 years of experience in public accounting, and works with some of the most successful venture capitalists in the world, helping to develop innovative financial strategies for business enterprises. Alan earned a B.S. in Accounting from Brigham Young University, and an MBA (Taxation) from California State University at Hayward. In 2005, Alan was honored by more than 7,000 Bay Area BYU alumni with a Public Service Award, recognizing his public service advancement and career accomplishments. That same year, he received the Chairman’s Award from the Fremont Chamber of Commerce.

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Morey Greenstein, CPA
Founding Partner

Morey Greenstein is the founding partner at Greenstein, Rogoff, Olsen & Co., LLP. The firm began in 1964 as a sole proprietorship and was among the first accounting practices in the new city of Fremont, California. In 1980, Morey opened a second office in Palo Alto to service his growing client base in the West Bay. Venture capitalists, real estate developers, merchants and professional practitioners were among the early clientele, many of whom remain clients to this day. Morey is actively involved in the accounting practice, specializing in wealth preservation strategies for individual clients and closely held businesses. Those clients that deal with Morey respect him for his technical expertise and practical approach to complex situations.

Steve Singer, CPA, MS
Partner

Steven Singer joined Greenstein, Rogoff, Olsen & Co. in 2003 and has more than 26 years experience in venture and corporate finance, mergers and acquisitions, high net worth individual, corporate and partnership taxation and strategic planning. Prior to joining the firm, Steve was V.P. of Finance for Callixa, an enterprise-based data integration software provider where he was responsible for all corporate finance and accounting issues. He has acted as interim CFO for numerous high technology firms and advisor for a variety of manufacturing, wholesale and distribution companies for whom he raised over $25MM in seed and venture capital. As Partner at Stadtler, Rosenblum & Saris, Steve concentrated on debt and equity planning, successfully negotiating improved rates and increased amounts on bank and institutional financings. Steve holds a B.S. degree in Business from U.C. Berkeley and a Masters degree in taxation from Golden Gate University.

Hal Friedman, JD
Partner

Hal Friedman was a Director with Greenstein, Rogoff, Olsen & Co., LLP for 16 years prior to becoming a Partner in 2007. For the past 24 years, Hal has been working as a tax professional and lawyer serving the greater Palo Alto area. His practice experience spans all areas of taxation including closely held corporations and their shareholders, individuals, expatriates and nonresident aliens, and professional practices. Hal holds a bachelor's degree in Accounting from Pennsylvania State University and a Juris Doctorate from Stanford Law School.

Ron Cohen, CPA, MST
Partner

Ron Cohen has more than 25 years experience in public accounting and related industry work. He earned an undergraduate accounting degree from the University of Illinois, Chicago, and then a Masters in Taxation from Golden Gate University. Ron has extensive knowledge in International Tax and has traveled extensively throughout Europe and Asia handling tax issues. He has also served as a tax director for a company with sales in excess of $2 billion. Ron teaches a course in taxation at Ohlone Community College. Ron lives in Fremont with his wife, who teaches English at Mission San Jose High School, and his two sons. Prior to his life as a CPA, Ron did some stand-up comedy in Chicago and received personal advice and coaching from Bill Cosby and Tim Reed. However, after observing that the vast majority of comedians have a very low taxable income, Ron decided to follow his father's example and become a CPA.

Scott Howard, CPA
Director of Accounting

Scott Howard is the Audit Director with Greenstein, Rogoff, Olsen & Co., LLP. For the past 12 years, Scott has performed audit, review and compilation services for a broad scope of clients including high-technology, HUD agencies, broker-dealers, financial consulting and non-profit organizations. With a high degree of specialization, training and commitment to benefit plan compliance, Scott has been chosen as the firm's technical expert in charge of AICPA's Peer Review Program which has resulted in an unqualified opinion every year.

Jeff Faust, AVA
Director of Business Valuations

Jeff Faust has more than 15 years experience in the finance and accounting fields with over 10 years in the valuation and stock option industries. Prior to joining Greenstein, Rogoff, Olsen & Co., LLP, Jeff was President of FT Solutions, Inc., a management consulting firm whose clients ranged from the small business and some of INC magazine’s 500 fastest growing companies to the pre-IPO and public companies. He has personally performed hundreds of business valuations for various purposes and has played key roles in the structuring of management buyout programs, management transition programs, stock option plans, and Employee Stock Ownership Plans (ESOPs). Jeff is a member of the National Association of Certified Valuation Analysts (NACVA) and has received the designation of Accredited Valuation Analyst (AVA). He is also an associate member of the American Society of Appraisers (ASA) and was elected Secretary for the ASA's San Jose Chapter for 1999-2000. Jeff holds a B.A in Economics from the University of California at Los Angeles.

Joyce Twomey, CPA
Continuing Education Program Director

Joyce Twomey has been a Manager at Greenstein, Rogoff, Olsen & Co., LLP for the past six years, and has been a practicing accountant since 1978. Joyce specializes in reviewing and preparing complex tax returns and creating effective tax strategies for closely held businesses and high net worth individuals. Additionally, her practice includes a focus on trust and CRUT services. Joyce’s commitment to the profession has led the firm to select her as the Continuing Education Program Director, creating and identifying professional learning and growth opportunities for all employees. Joyce currently serves as an ambassador with the Fremont Chamber of Commerce and is a member of the California Society of Certified Public Accountants.

Karifa Diawara, CPA, MS (tax)
Director

Born in Guinea, West Africa, Karifa was educated in France, receiving both his BS and MS in Economics and Management (with emphasis in Accounting and Finance) from the University of Reims, France. He received his Masters in Taxation from Golden Gate University. Karifa has over 10 years experience in the Accounting profession and holds a California CPA license. Prior to joining Greenstein, Rogoff, Olsen, & Co., Karifa was a manager at a regional CPA firm based in San Mateo. Karifa has a unique career that includes working for the United Nations in Ethiopia providing management and accounting training for local business owners. Karifa currently serves as a member of the board of directors of Samaritan House, a San Mateo county non-profit organization helping those in need.  He is also a member of the California Society of Certified Public Accountants (CalCPA) and the American Institute of Certified Public Accountants (AICPA).  Karifa is a private pilot and speaks seven languages.

Mary Kay Foss, CPA
Director

Mary Kay Foss has over thirty years of practical experience in advising clients on retirement, income and estate planning issues. Ms. Foss is a frequent lecturer for community, professional and business groups, and has authored and presented courses for tax professionals throughout California. She is a past chair of both the Estate Planning Committee and the Committee on Taxation for the California Society of Certified Public Accountants. Ms. Foss is also the past president of the Estate Planning Council of Diablo Valley, the East Bay Chapter of the California CPA Society, and the Estate Planning Council of the East Bay. Ms. Foss teaches courses for the California CPA Education Foundation and has been quoted in local and national industry publications. She is also a member of Danville Rotary and Treasurer of the Hospice of the East Bay Foundation.