My naturalized Canadian citizen in-laws have now became naturalized US citizens. They have been getting old age security payment since they became Canadian citizens. Now they're US citizen as well. Are they eligible to collect SS payment in US? They haven't worked in both countries. Main purpose of applying for SS benefits is to get the Medicare and Medicaid. Do we have to show Canadian payment when we apply for SS benefits in USA? Will that make their application more or less problematic?