While most Americans are required to obtain health insurance under Affordable Care Act’s mandate, others are exempt from purchasing insurance by joining medical bill-sharing groups, the Miami Herald reports. According to the Congressional Budget Office and the staff of the Joint Committee on Taxation, about 7 million Americans in bill-sharing groups are exempt from buying other insurance or paying a penalty. As an example of this type of arrangement, the Herald offers an example of a baby whose treatment at West Boca Medical Center in Palm Beach County totaled nearly $100,000 and was paid for by the Melbourne-based, not-for-profit Christian Care Ministry Medi-Share.