Lew grew up in Winchester and graduated from John Handley High School. During his teenage years he lived and worked at LaGrange Farm in Stephens City building fences, tending cattle, making hay, and learning basic bookkeeping for his custom hay baling business. He was also a dedicated Boy Scout, serving on the staff of Camp Rock Enon and obtaining the highest rank in Scouting - Eagle Scout. In 1980 Lew received his B.S. in Accounting from the University of Virginia in Charlottesville, VA. His first job was as a staff accountant with Surles & Associates in Warrenton, VA. In May 1981, he married his wife, Liz, who was finishing her education at UVA. He returned to Charlottesville, working at Salley, Weissinger & Co for the next 3 years. He became a licensed CPA in 1982. In 1984, after starting a family, Lew and Liz moved to Winchester so Lew could “hang out his own shingle”. For the next ten years Lew was in partnership and/or associated with several local CPAs. In 1994 Lew opened his solo practice, Lewis M Costello, CPA, PC. Liz was his first employee, beginning as a bookkeeper in 2002. The support staff grew along with the practice until 2014 when Christine Allen, CPA became a professional associate. Lew's area of expertise is taxation. He specializes in providing expert tax guidance and consulting to individuals, businesses, estates, and trusts. Lew also provides estate planning and administration services. Lew has been a member of the American Institute of Certified Public Accountants (AICPA) since 1983, and a member of the Virginia Society of Certified Public Accountants (VSCPA) since 1982. His community service has included 6 years as an elected board member of the Lord Fairfax Soil & Water Conservation District, 8 years on the Lord Fairfax Community College Educational Foundation Board, 5 years as a member of the Winchester/Frederick County Jaycees, and over thirty years serving his church - First United Methodist Church in Winchester. Outside of work, Lew enjoys singing with his church choir as well as Winchester Musica Viva, the Piedmont Singers, and the Consonants. He also spends time hunting, traveling as much as possible, and being with his family and three grandsons.

Liz spent her first 18 years in Nutley, NJ until going to college at the University of Virginia. She met Lew in 1979 and they married in 1981. Liz received her B.A. in Psychology in 1982. Amy was born in Charlottesville in 1983 and the following year, the family moved to Winchester. Two more sons followed - Daniel in 1985 and Ethan in 1990. From 1984 to 2000 Liz was a full-time homemaker and held various part-time jobs including day care, retail and administrative positions. She then worked full-time at Impressions Plus in Winchester until joining Lew at the firm in 2002. Liz sings with her church choir, Arts Chorale of Winchester and the Piedmont Singers. She enjoys traveling, gardening and spending time with her family, especially her three grandsons. She is a founding member of Cheers 2 Charity, an organization devoted to organizing, assisting and holding fundraisers to support and raise money for other Winchester charitable organizations.

Daniel graduated from John Handley High School in 2003. He received his Associates Degree in Liberal Arts from Lord Fairfax Community College in 2006 and studied accounting at LFCC from 2011-2013. Before joining the Firm in 2011 he worked for over 6 years with children ranging in age from 6 weeks to 13 years at CHEERS School Family, Inc. as well as the Heritage Clubhouse in Berryville, Virginia. Daniel does bookkeeping and payroll work, tax return preparation, and property management services for several family owned rental properties. Daniel is also a shareholder and officer in TNT Property Management, Inc. While not at work, Daniel and his wife, Samantha, love to play with their two dogs and two cats. Daniel sings with the Consonants and the Piedmont Singers. He also plays drums and guitar, and enjoys reading and history, especially relating to the Civil War and World War II.

Becky was born in Winchester and graduated from James Wood High School in 1986. She is an alumnus of Radford University where she achieved a B.B.A. in Accounting. She started her accounting career with Lew right out of college. She worked for his local CPA firm a few years before leaving public accounting for the private small business sector. Over the years, Becky has provided bookkeeping, HR and office management services to local entities. In 2017, she became re-established with Lew and the firm, assisting with bookkeeping and tax return preparation. Becky and Joe have two adult children, Lyndsey and Cody. She loves spending time with her family and friends and enjoys traveling. Becky serves on the board of the Top of Virginia Honor Flight.