An advance beneficiary notice is required in which of the following cases?

An advance beneficiary notice (ABN) is specifically required when a Medicare patient is scheduled to undergo a procedure or test that Medicare might not cover. The ABN serves as a legal document to inform the patient that Medicare may not pay for the service, allowing them to make an informed decision on whether to proceed. This process not only protects the patient's rights but also ensures that they understand their financial responsibilities if Medicare denies payment.

In contrast, the other options presented do not warrant the issuance of an ABN. For example, treating a patient with a common illness like a cold typically aligns with standard covered health services under Medicare guidelines, while routine blood work is also generally covered. Emergency services provided to Medicaid patients are similarly designed to ensure access to care without the precondition of an ABN, ensuring they receive necessary treatment even if there are questions surrounding coverage. Thus, the requirement for an ABN is primarily applicable in scenarios involving potentially uncovered services for Medicare patients, which consolidates the focus on informed consent and transparency in healthcare.