Objective: Study occurrence and consequences of deductibles and medical debt among privately insured under the Affordable Care Act. Methods: Analysis of 2012–2016 National Health Interview Survey data on privately insured adults younger than age 65 on the effect of deductibles on medical debt, deferred medical care, and office visits, by demographic characteristics, and treatable chronic diseases. Results: Rates of medical debt and deferred care decreased. Medical debt is greater for those with any type of high deductible (HD) insurance, and among those more vulnerable (lower income, minority, treatable chronic diseases). Medical debt with HD's increased deferred needed medical care 6 fold and is highest for those with more treatable chronic diseases. Conclusion: While medical debt and deferred care decreased for all privately insured, those HD-insured and vulnerable report higher medical debt rates markedly increasing deferred needed medical care. Highdeductible insurance risks adverse health and social consequences for those vulnerable.