It is important to apply for EI benefits within 4 weeks of your last day of work in Canada. If you delay in applying, then you risk losing benefits.

Employment Insurance (EI)

FAQs: Employment Insurance (EI)
Website: EI – Workers and residents outside of Canada - Overview

When moving outside of Canada, spouses and/or dependents may be covered by Canada’s EI system. You will need to obtain an Employment Authorization Document (EAD) and SSN, to be eligible for EI benefits, as you need to show proof that you are able and willing to work in the U.S. 

It is recommended that you call the Service Canada Interstate Department once you know you are being posted OUTCAN to the U.S. as each case is different.
That # is: 1.877.486.1650
Please see the EI FAQ for more detailed information and steps on how and when to apply for EI while OUTCAN U.S.

Returning to Canada?
If you are returning to Canada, you may be eligible for EI benefits if you worked outside Canada for a Canadian company or Canadian government. Call the CRA for more information at: 1.800.959.5525

If you worked for a U.S. company during your OUTCAN, you may be eligible to claim American Unemployment Insurance benefits. Please contact your state's Workforce Development Agency. For more U.S. Benefits Information CLICK HERE.