Which of the following is an example of healthcare abuse?

Charging in excess for services rendered is a clear example of healthcare abuse because it demonstrates unethical financial practices that exploit patients or the healthcare system for financial gain. This behavior undermines trust in healthcare providers and can lead to inflated healthcare costs for patients and insurers alike.

In the context of healthcare, abuse typically involves practices that may not be fraudulent but still result in unnecessary costs or inefficient use of services. Charging excessively for services takes advantage of the patient’s or insurer's lack of knowledge about standard rates and fair pricing and can lead to serious financial distress for patients.

The other options represent situations that are either not intentional, ethical ways of managing costs, or practices that aim to aid patients rather than exploit them. For instance, accidentally filing claims for unnecessary services may indicate negligence but doesn't necessarily rise to the level of abuse. Providing the lowest-cost supplies suggests a commitment to cost-effectiveness, and offering discounts for uninsured patients aims to make healthcare more accessible, both of which demonstrate ethical practices rather than abusive behavior.