Examples of fraud schemes perpetrated by health care institutions and their employees include all the following EXCEPT:

Unintentional misrepresentation of the diagnosis stands out as the choice that does not fit within the typical framework of fraud schemes perpetrated by health care institutions and their employees. Fraud schemes generally involve intentional actions aimed at deception for financial gain. In contrast, unintentional misrepresentation implies a lack of deliberate intent to deceive, often stemming from misunderstandings, clerical errors, or lack of proper information.

Fraudulent schemes like DRG creep, billing for experimental procedures, and improper contractual relationships are characterized by intentional misconduct. DRG creep refers to the practice of hospitals coding for more complex diagnoses to receive higher reimbursement rates than patients actually require. Billing for experimental procedures typically involves charging for treatments not supported by evidence or outside the scope of what insurance covers. Improper contractual relationships can lead to conflicts of interest and inappropriate financial benefits, which are also intentional manipulations intended to gain financial advantages.

In summary, the nature of unintentional misrepresentation contrasts sharply with the purposeful and deceitful actions that define health care fraud, making it the exception in this context.