Cornerstone Specialty Insurance Services, Inc.
14252 Culver Drive, #A299
Irvine, CA, 92604
Phone: (714) 731-7700
Fax: (714) 731-7750

Cornerstone Specialty Insurance Services, Inc.

Staff Bios

Lisa Greenberg, President

Tina Cowie, Vice President

Aimee Guesno, Account Manager


Lisa S. Greenberg, CIC - President

Lisa Greenberg is Founder and President of Cornerstone Specialty Insurance Services, Inc., and provides insurance counseling and risk management to her clients along with a broad range of products and services.

Lisa began her career as a State Farm agent in 1983; at that time she concentrated on personal lines insurance for individuals.  In 1985, Lisa transitioned to her specialization in dealing with the complex needs of design professionals and the construction industry.  With close to three decades of experience, Lisa has the expertise to find the appropriate insurance programs in the market place for a wide variety of businesses. This includes her ability to negotiate highly competitive rates with almost all the leading insurance companies. Lisa also provides risk management, contract review, and seminars for her clients. 

Lisa has earned the designation of Certified Insurance Counselor (CIC), the insurance industry’s premier source for practical, real world education for insurance professionals since 1969.  She is currently working on obtaining her Certified Risk Managers (CRM) designation.

A Southern California native, Lisa lives in Orange County, where she coaches girls’ basketball and soccer in her spare time.  She is an avid soccer fan!


Tina Cowie, CIC, CISR, ACSR - Vice President

Tina Cowie is Vice President of Cornerstone Specialty Insurance Services, Inc.  She began her career in 1978 as a file clerk for a major insurance company and rapidly advanced to the role of Assistant Personal Lines Underwriter.  In 1980, Tina moved to the agency side of the business; she has been Vice President of Cornerstone since 2003.

With over three decades of insurance experience, Tina has the ability to understand and evaluate the insurance needs of various types of businesses, from auto repair shops to architecture firms. Tina Cowie has earned the designations of Customer Insurance Service Representative (CISR), Accredited Customer Service Representative (ACSR) and Certified Insurance Counselor (CIC).

Tina is a Southern California native. She and her husband, John, have been married since 1979 and have three wonderful sons.


Aimee Guesno, CISR - Account Manager

biopic Aimee1Aimee Guesno is an Account Manager at Cornerstone Specialty Insurance Services, Inc., where she began her insurance career in 2004. She has earned the designations of both Certified Insurance Counselor (CIC) and Certified Insurance Service Representative (CISR).

Aimee was born and raised in California. She's an improv comedy artist, loves all kinds of music, and (of course!) she's a soccer fan.