Co-insurance is the amount that the insurance company does not pay, after the deductible has been met. When a patient has met their deductible, they will still be responsible for a reduced amount when they receive medical services and treatment. Typically, the insurance will pay a percentage (i.e. 80%) of the charges, and the insured member is responsible for the remaining percentage (i.e. 20%). Both deductible and co-insurance are considered cost share obligations on applicable insurance plans. Coinsurances have fewer restrictions regarding a ‘write-off' by a doctor.
Part of the "Understanding Insurance" series.