Buying a good medical insurance for visitors is a wise decision and is not an under statement. First of all, any visitor medical insurance plan is as good as the acceptability of the provider in locales such as USA or Canada when the visitor is in dire need of critical emergency care. If this does not hold ground, however cheap any policy is does not matter, as this may apply to non-US plans at cheaper quoted premiums with doubtful plan availability. Ascertain this first before you decide on any plan. In general, buying a visitor insurance plan from a US based provider is in your best interest as these plans are better regulated and offer wider acceptability.