Hello Angela, Katrina from WorldNomads.com here.
It really depends on what's happened as not every situation is covered under every policy.
Usually you would pay for your expenses and make a claim using our online tool:
If it is a covered expenses according to the terms of the policy you bought, you would then be reimbursed for your costs.
If you are hospitalised, and it's a covered expense/situation, your insurer can work directly with the hospital to negotiate and pay the bills.
Its always best to keep a copy of your policy certificate when you travel (and give a copy to friends/family), so if anything happens, you or someone else can call your insurer's emergency assistance company and they will tell you how the insurance can help.
Here's a list of the assistance companies our insurer's use (which are different based on your country of residence): http://www.worldnomads.com/emergencyassistance.aspx
The policy wording/full description of coverage will give you all of the details on how the policy works and how to make claims.
If you have any specific questions about what's covered and when, then please contact our customer service team: http://worldnomads.com/members/memberscontactus.aspx
Katrina about 7 years ago