Example: Amy received $12,000 in annuity payments of which $7,000 was allocated to her investment in the annuity. As a result, pursuant to IRC Section 72(b), Amy would exclude $7,000 of the payments from gross income and net investment income. The difference between the total annuity payment of $12,000 and her $7,000 basis, or $5,000, would be included in gross income and in net investment income, subject to the net investment income tax.