What is the name of the diagnostic department led by Gregory House in House M.D.?

Gregory House leads the Department of Diagnostic Medicine in House M.D. The department specializes in difficult cases that remain unexplained after routine examinations and consultations.

Unlike a conventional specialty department, diagnostic medicine in the series draws physicians from multiple fields. House and his fellows use differential diagnosis, laboratory testing, imaging, observation, and sometimes risky procedures to identify the underlying disease. The department's small team structure allows the show to dramatize debate over competing hypotheses.

The fictional department is one of the series' defining inventions. It provides a story reason for House to encounter unusual cases involving neurology, infectious disease, immunology, toxicology, and many other areas. In real hospitals, complex diagnosis is usually distributed across specialists rather than assigned to one identical department.

The department is sometimes called “diagnostics” in dialogue, but its formal name is Department of Diagnostic Medicine. It should not be confused with House's clinic duty, which is a separate recurring obligation imposed by hospital administration.