Enrollees in large employer health plans with inpatient admissions receive an out-of-network medical bill approximately 18% of the time, according to an analysis released today by Kaiser Family Foundation. Individuals who receive inpatient or outpatient care for mental health or substance use are much more likely to have a claim from an out-of-network provider than other large plan enrollees. About one in three inpatient admissions claims for psychological and substance use care included an out-of-network provider, compared with about one in five claims for surgical and medical care and one in 10 for childbirth and newborn care, the authors said. The Affordable Care Act includes a provision requiring health plans to periodically report cost sharing and payment data on out-of-network coverage, but the provision has yet to be implemented, the report notes.