Check out page 16 of the Getting it Right guide:
Income of the applicant. If an application relates to a one- to-four- family dwelling, enter the total gross annual income your institution relied on in making the credit decision. For example, if your institution relied on an applicant’s salary to compute a debt-to-income ratio, and also relied on the applicant’s annual bonus to evaluate creditworthiness, report the salary and the bonus. Report the amount in thousands, rounded to the nearest thousand ($500 should be rounded up to the next thousand).
Enter “NA†if
—your institution does not take the applicant’s income into account,
—the loan or application is for a multifamily dwelling,
—the transaction is a loan purchase and you choose not to collect the information,
—the transaction is a loan to, or application from, an employee of your institution and you seek to protect the employee’s privacy, even though you relied on his or her income, or
—the borrower or applicant is a corporation, partnership, or other entity that is not a natural person.