What must an insurer obtain before testing an applicant for HIV?

An insurer must obtain written consent from the applicant before testing for HIV because this is a matter of confidentiality and individual rights. Written consent ensures that the applicant is fully informed and agrees to the testing process, including the implications of their results. It protects both the applicant's privacy and the insurer by documenting that the applicant has voluntarily agreed to the testing, which is crucial in maintaining trust and compliance with legal and ethical standards.

This requirement helps to ensure that applicants understand what the testing entails and how the results will be used, aligning with regulations around informed consent. Written documentation is also significant in case there are any disputes or misunderstandings regarding the testing process. The other options do not provide the necessary legal protection or formal acknowledgment needed for such sensitive medical testing.