What is an excess?
The excess is the amount of each medical bill that you will pay. For example if you medical bill is HK$2,000 and your excess is HK$500 then you would pay the first HK$500 of any bill, leaving HK$1,500 of this one to be covered by your medical insurance. If you have a higher excess then the medical insurance pays less of the bills, so the medical insurance is cheaper.