jay_snair

Consider a person sent to US on B1 visa by his company in India. I understand that the allowances he receives in the US while on B1 is not taxable in the US. If the company decides to convert his visa to L1, subsequent to which he will be paid a salary in the US that is taxable, how will the income while on B1 be treated for the purpose of taxation? Specifically, will the allowances while on B1 become taxable along with the salary while on L1? If not, is it required to disclose the income while on B1 in his tax returns at all?