An examination of billing policies and practices at more than 500 hospitals across the country shows widespread reliance on aggressive collection tactics.

Even after their babies died, hospital bills kept coming. These parents of fragile, very sick infants faced exorbitant bills — though they had insurance. "The process was just so heartless," one says.

For one South Dakota mom, cancer treatment saved her life, but left her $30,000 in debt. The cost of care in the U.S. can make patients drain savings, declare bankruptcy, or lose their homes.

Whether a simple operation is performed under the auspices of a hospital or at an independent surgery center can make a huge difference in cost.

Only 15 states require insurance to cover in vitro fertilization, a pricey path to parenthood. But expensive procedures and drugs can lead to unexpected bills even for the fortunate who are insured.

After baby Dorian Bennett arrived two months early and spent more than 50 days in the neonatal ICU, his parents received a bill of more than $550,000 — despite having health insurance.