Depends on who you ask. Before Obamacare if your employer didn't pick a great insurance plan and you got seriously sick the insurance could cut you off after you hit a lifetime maximum and then future policies wouldn't cover that specific condition because it was considered pre-existing.

This happened to my parents in the 90s and we went through multiple lifetime maximums and had to pay hundreds of thousands of dollars over the course of 10 years.

Obamacare is great for making health insurance actually act like insurance.