Broker Check

Our Team

Tim Thornberry



Tim has been in the financial services industry for 14 years and partner and co-founder of Cornerstone Financial Partners, LLC. He believes that trusted guidance is built by being committed to serving others.

Accustomed to serving, Tim spent eight years in the Marine Corps reserve. He valued his role as a Platoon Sergeant as an opportunity to lead and develop young Marines. He deployed in 2003 as part of the 26th MEU(SOC) and again in 2006 with CLR-15 to the AL Anbar province Iraq. Now finished with his military career, Tim serves on the board of trustees of the Enterline Foundation and Hi-Hope Service Center. Both nonprofits work to improve the lives of individuals with developmental disabilities. Tim is also the Vice Chairman of the Gwinnett County Zoning Board of Appeals.

Tim graduated from North Georgia College and State University and he has an MBA from the University of Georgia’s Terry College of Business. He has traveled to 22 countries and enjoys seeing new perspectives. Tim has a wonderfully inquisitive son, Alexander and a sweet girl, Lucy.

Tony DiMatteo



Tony DiMatteo joined Cornerstone in 2019.  He has known Tim, the founder, for 14 years.  Tony has decades of experience investing in stocks, bonds, mutual funds and other assets.  He has owned and operated several businesses, including a daycare, a construction company and a consulting firm.  In prior years, Tony had management roles in technology companies ranging from start ups to Fortune 500 firms.  He attended Rutgers University and his studies qualified as a triple major – Business Administration, Computer Science and English.  He hopes to have several of his novels published one day.

Tony has two daughters he is proud of, Nicole who is a nurse, and Nina, who is in hotel management.  Tony and his wife Roxane actively support several causes, including animal rescue, which is near and dear to their hearts.  They currently have three rescue dogs, each with their own unique and inspiring story.

Tony is committed to his clients’ financial well being.  He is passionate about helping clients prepare for the future and navigate through their seasons of life.  He has pinpointed experience helping seniors and widows and widowers manage the stressful challenges they encounter.

Michael Steck



After 38 years of experience in Financial Services, I still look forward every day to studying influences on the financial environment and guiding clients to realize their aspirations.

 A graduate of the College of Business Administration at St. John’s University, I began my career in retail executive management with Federated Department Stores. Participating in the management of a 585,000 square foot department store was thrilling! Nevertheless, my education was economics, and my dedication was always finance, so I made a career change – which I continue to value. I recently merged my business with Cornerstone, and I’m thrilled to join as a Partner with this very successful group.

 With a passion for baseball – which I played through college – I have continued to enjoy the game vicariously by coaching at the youth level for many rewarding years. Now I never miss an opportunity for a tennis match!

Giving back is important to me. I have been enthusiastically involved with St. Jude Children’s Research Hospital, participating in fundraising and awareness campaigns, for the past 18 years, ever since my wife, Salli LeVan, joined the Board of Directors of St. Jude. I have also been a supporter of Year Up, an organization that provides opportunities for disadvantage young adults, by offering seminars in basic money management.