Your vet should get in touch with you when they get results back from KS. My vet got the results faxed first (which doesn't really matter since you need the original form from KS), and about a week later got the form in the mail.
After you get the form, your vet can fill out the sections in the EC998 form saying that they've seen documentation proving that the microchipping, vaccination, and bloodwork are all in order.
In another few months, you'll bring the EC998 form, the proof of microchipping, the rabies certificate, and the FAVN form from KS to your USDA vet who will sign off on the EC998 form that all the documentation checks out. After that, you hand over all that paperwork to the airline when you check in. (Plus anything else they might need, BA wanted a health certificate from my vet saying my pets were ok to fly.)
Hope that helps!
