Glaring differences in insurance coverage persist for amputees, children with autism and others in need of certain expensive treatments even after the Affordable Care Act set new standards as part of its push to expand and improve coverage, and despite efforts by states to mandate coverage for some treatments.

These differences don’t develop simply because some people pay more for better coverage. Instead, they stem from random factors like what state someone lives in or who happens to provide their coverage — and often people can do nothing about it.

These gaps can bury patients in debt or force them to skip care. And they may become more common as health care costs continue to rise and insurers and employers look for ways to control that expense.