Serbinski Accounting Firms

Once I obtain this CPP compliance letter, do I send this to the IRS? Am I still required to complete the forms that they sent me?

I am a Canadian citizen living in Canada but working for a US company. I have been working in this situation for the past 6 years and have been paying Canadian taxes each year. I occasionally travel to the US to work at the US company's headquarters. No more than 1 or 2 weeks each year. I have a TN ...