The Charitable Lead Annuity Trust, Charitable Remainder Annuity Trust, and the Grantor Retained Annuity Trust all need to perform an exhaustion test. This test can be performed using one of two different methods:
The IRS Annuity Factor Method This is the method which appears to have been used by the IRS in §25.7520-3(b)(2)(v), Example 5. It uses published annuity factors to determine when the trust exhausts, and what the payment is in the last period of the trust.
The Illustrated Method This method creates the schedule of payments based on the assumption that the trust will grow at a rate equal to the §7520 rate. You can use this method to illustrate when the annuity is expected to exhaust.
The program defaults to using the IRS Annuity Factor method to best reflect §25.7520-3(b)(2)(v), Example 5.