You may be able to cut your costs between jobs.

Since Ms. Raff has become an independent contractor, she's looking to buy her own insurance coverage. That's not the only time when consumers can be startled by the price of Cobra.

If you're switching jobs, you may have to wait a month or more before the health benefits at your new employer kick in. If your current coverage runs out in the meantime, your options will generally include Cobra coverage, buying a short-term policy or taking a risk and going without insurance during that period.

If you're healthy enough to go without medical care for a while, you may be able to avoid spending anything -- and still know you have a safety net if you really need it. "You can wait to see if you have a problem and sign up for Cobra retroactively," says Gary Claxton, director of the Kaiser Family Foundation's health-care marketplace project.

Here's how that works. Once your health benefits have ended or you're provided a letter saying you're eligible for Cobra (whichever comes later), you normally have 60 days to sign up for Cobra. When you sign up, the coverage is retroactive to the first day you would have otherwise lost your former employer's coverage. If your health benefits at your new company start before you've signed up for Cobra, then you'll have gotten through your gap in coverage without spending anything.

This technique isn't without its risks, however, especially if you push the 60-day limit, Ms. Pollitz says. Among the potential snafus: You could get into a serious accident and not sign up before the 60th day comes and goes. Then you'll have been to the hospital, and the bill will normally be yours alone.