About Us

Don W. Amstrong CPA, Inc. - Your CPA firm in Norman who understands small business.

About Us


For more than 40 years we have been meeting the needs of small businesses and individuals with respect and professionalism. As always, there is no charge for our initial consultation.

Meet Don Armstrong

Don was born in Texas. He served in the military before attending and graduating from the University of Baltimore. Don worked for a national CPA firm before he became partner in serveral local CPA firms. Over the years, Don has gained first-hand business experience through ownership of many different enterprises. These include accounting, payroll, hospitality, manufacturing, construction, and real estate management and syndication.



Meet Michelle Linnemann

Michelle was born in Augsburg, Germany while her father served in the U.S. Air Force but at an early age moved to Norman, OK where her mother’s family had lived for several generations. As a child, Michelle was a competitive roller skater competing all over the south central United States. Later, as an adult she continued her roller skating career by turning professional and teaching for several years. Many of her students, including her young son qualified for national competition.

Michelle is a 1974 graduate of Norman High School and after retiring from the skating world she pursued a degree in Accounting attending Rose State College and the University of Oklahoma. She has over 30 years experience in the accounting and payroll industry, and has owned or co-owned businesses that range from an antique store to a veterinary hospital. She has been active on several boards and committees including, Automobile Alley in OKC, The Heart of Norman, Norman Downtowner’s, Norman 89er Day Parade and The Performing Arts Center.

Michelle is the mother of a grown son, Rhett, a teenage daughter, Mikayla and has a teenage grandson, Seth. She is a member of St. Michael’s Episcopal Church, Business Networking International, and other professional organizations. In her spare time, she enjoys studying history, genealogy, reading and antiquing.


Meet Sherry Hill

Sherry has lived all over the world, but her parents are from Oklahoma, so this has always been her "home."

Sherry enlisted in the Air Force (ours!) in 1972 during the Vietnam War. She was stationed exotic places, such as North Dakota and Missouri. That was enough for her, but she really did enjoy her enlistment.

Sherry went to college in South Dakota but moved to Oklahoma in 1992. She owned several businesses before settling down to work for Don Armstrong, CPA. She has worked here twenty years! Don Armstrong started Access Payroll in the late 90s, and it was absorbed by Diamond Payroll in 2008. She has been with the company since its inception.

Sherry has two sons, but she's now happily single. She gardens and cooks for fun.

In her spare time (ha ha), she is the treasurer for Boomer Nooner's Toastmaster Club, Secretary/Treasurer for the Business 2 Business chapter of Business Networking International, and Treasurer for Cleveland County Habitat for Humanity.

Through Don Armstrong CPA, she is an affiliate of the Norman Board of Realtors. She helps raise money every year for college scholarships for local high school students.

Through Diamond Payroll,she is an affiliate of the Builders Association of South Central Oklahoma. 

Meet Lauren Walls, CPA

Lauren was born and raised in Texas. She moved to Oklahoma with her husband and daughter in 2000, and in 2009 was blessed with a second daughter.

Lauren graduated from the University of Texas at Arlington in 1995, where she simultaneously obtained her BS in Accounting and her MS in Taxation. She worked thru college as a bookkeeper, gaining valuable experience in small business accounting. She has over 25 years of experience in bookkeeping, accounting and/or tax research, planning and compliance, with the last 15 of those years licensed as a CPA serving clients in various industries including oil & gas, non-profit, restaurants, retail, and medical, as well as many others. Lauren joined our firm in 2014.

Lauren educates both her daughters, ages 17 and 6, and is involved in several volunteer roles within the Norman homeschool community. She is also an active member of McFarlin United Methodist Church. Her other interests include gardening, reading, and cooking.




















Call us to schedule a consultation: 405.321.7621