When you purchase travel insurance before a big trip, most likely you're hoping you don't ever have to use it, but it can be a big help if you get sick or injured far from home -- or even before you leave. If you've purchased the travel insurance available when you book a Priceline airplane ticket and now need to use it, you'll have a bit of research and information-sharing to do to make sure you get the payout you paid for.

Read the Priceline insurance "Description of Coverage" document carefully to ensure the cancellation you want to make will be eligible for insurance coverage. Generally, Priceline's travel insurance -- administered by BerkelyCare, as of the date of this publication -- will cover your trip expenses if you, a business partner, your immediate family members or travel companions experience an illness or injury that requires the care of a physician. You want to make sure you know exactly what is covered, so read the document carefully.

Call Priceline's Customer Service Department to cancel your reservation. Inform the agent you speak with that you plan to file a travel insurance claim for the trip. Depending on the circumstances, you may get a partial refund for your reservation.

Obtain a note from the attending physician stating the medical condition that prevented you from making your trip. Include the dates of the illness or injury and the name of the person treated.

Contact BerkelyCare immediately to begin a travel insurance claim. While you have 90 days following the trip cancellation, the sooner you get the ball rolling on your claim, the better. Use the "Description of Coverage" document to get the contact email and telephone number for BerkelyCare's claims department. BerkelyCare will send you a form to fill out and ask you to provide supporting documentation, such as the doctor's note, for the claim.