Verification of benefits (VOB) is a document provided by health insurance companies detailing coverage and eligibility for specific medical services. It typically includes information such as deductible amounts, co-pays, and coinsurance percentages. VOBs help patients understand what portion of medical expenses their insurance will cover and any out-of-pocket costs they may incur. They are essential for healthcare providers to determine the patient's financial responsibility before providing services. VOBs assist in avoiding billing errors and ensuring accurate reimbursement for healthcare services rendered.