Also known as: siu definition · siu insurance · special investigations unit
A Special Investigative Unit (SIU) is the team inside an insurer that investigates claims it suspects may be fraudulent or misrepresented.
A Special Investigative Unit is a dedicated department that carriers use to detect, investigate, and refer suspected insurance fraud, and many states require insurers to maintain one. When a claim is flagged with red flags, the SIU may request additional documents, examine your loss history, interview parties, and coordinate with regulators before the claim is paid. For an honest startup this is rarely a problem, but it is why accurate applications, clean records, and prompt cooperation matter, since inconsistencies can move an otherwise straightforward claim into an SIU review.
An SIU, or Special Investigative Unit, is the group within an insurance company responsible for investigating claims that show signs of possible fraud or misrepresentation. Many states legally require insurers to operate an SIU as part of their anti-fraud programs.
Claims are typically referred to the SIU when they contain fraud indicators such as inconsistent statements, a loss that does not match the reported facts, unusual timing after a policy change, or a history of similar claims. Referral does not mean you did anything wrong; it means the insurer wants to verify the details before paying.
Cooperate fully, provide the requested documents promptly, and keep your answers consistent with your original application and notice of claim. Your policy's cooperation clause generally requires reasonable assistance, and working with your broker keeps the process moving toward payment.
Definitions are educational and may be modified by your specific policy language, endorsements, and state rules. For regulatory guidance, refer to the California Department of Insurance or the NAIC.
Last updated: July 2026.