What type of investigations are conducted for positions requiring access to classified information?

The type of investigations conducted for positions requiring access to classified information is background investigations. These investigations are comprehensive processes designed to evaluate an individual's reliability, trustworthiness, and loyalty to the United States.

Background investigations scrutinize various factors including an individual's criminal history, financial status, employment history, and social relationships. This thorough vetting ensures that only those who meet specific security standards are granted access to sensitive information, thus safeguarding national security.

Other options, while relevant to certain aspects of employment or personnel assessments, do not focus on the critical elements related to national security vetting. Performance reviews assess job performance rather than security eligibility, reference checks verify an individual’s qualifications but do not delve into the deeper security concerns necessary for classified access, and health assessments primarily focus on medical fitness rather than the security aspects of an individual's background.