Happy 22nd birthday! Now, are you ready to shell out the money for health insurance?

Most young adults are no longer covered under their parents' insurance policies once they reach age 22 or cease to be full-time students, says Madelyn Flannagan, spokeswoman for the Independent Insurance Agents & Brokers of America.

Many 20-somethings, including recent college grads, hold off buying health insurance until they land a full-time job with benefits. "So, many can't find insurance, or they don't want to pay the price," says Flannagan, who adds that an individual policy can cost more than $400 a month.

But that's a gamble they shouldn't take in a world where the average cost of a one-day hospital stay is $3,000. An appendectomy can be more than $12,000.

If you're in this situation, some options you have include a Cobra extension of your parents' policy, student insurance through insurance agencies or your university, short-term insurance or individual long-term policies. Each type has benefits and downsides, says Flannagan, but you should choose a policy based on what you can afford each month.

If you're searching for health insurance:

Get copies of all relevant records from your parents. Your new provider will want background information on what medical treatment and insurance coverage you have received.

Make sure there isn't a time lapse between when your parents' coverage ends and when your new policy begins. Flannagan says avoiding this is especially important if you have a pre-existing medical condition such as asthma or allergies. It often takes time for pre-existing conditions to be covered under a new policy, and you won't want to pay full-price for those prescription medications.

Ask about benefits at your current job, even if you're working part time.