Associated with Mayo from 1908 until 1952, Harry J. Harwick was the key figure in developing the concept of lay administration. As a protégé of Dr. William J. Mayo, he fostered the evolution of medical administration as an enhancement to group practice that frees the physician from the daily burdens of routine business affairs.

In 1908, the Mayo brothers needed an assistant to William Graham in their business office. Dr. Will hired Harwick for the post. Graham had headed the Mayos' business operations since 1901. After Harwick was hired, he assisted Graham in routine business matters. He also began to modernize the accounting system, as Dr. Will had suggested when Harwick was employed. In consultation with Graham, Harwick introduced a ledger system to replace the system then in vogue.

The new accounting system was only the beginning for Harwick at Mayo. During his more than four decades at Mayo Clinic, he helped to establish Mayo Foundation and develop the financial stability of Mayo and its enterprises. After the death of the Mayo brothers in 1939, he was appointed the Chief Executive Officer of the Mayo Board.