If you are a W-2 employee of a consulting firm, the lender usually starts with pay stubs, W-2s, and a verification of employment. If you are paid on a 1099, or you invoice through your own entity, the lender may treat you as self-employed and ask for tax returns or a bank-statement program. Corp-to-corp arrangements need the contract and a paper trail from the client to your account.
Fannie Mae B2-2-02 does not require a set number of years left on the visa. A lender can still ask for the visa, the I-94, and an employer letter. We will not tell you that every consulting file is approved.