The IRS has garnish part of my $627.00 social security disability payments, leaving me with $526.00 a month to live on, can they do this.

In Canada, Revenue Canada can seize old age security, canada pension, any payments that come from government sources for debts to RevCan, so I guess, yes, IRS can do it in the States as well. But usually they give you an option of paying it off another way. Did you disregard their offers of alternate payment plan ?