Past-due benefits means the total amount of benefits under title II of the Act that has accumulated to all beneficiaries because of a favorable administrative or judicial determination or decision, up to but not including the month the determination or decision is made. For purposes of calculating fees for representation, we determine past-due benefits before any applicable reduction under section 1127 of the Act (for receipt of benefits for the same period under title XVI). Past-due benefits do not include:
(1) Continued benefits paid pursuant to § 404.1597a of this part; or
(2) Interim benefits paid pursuant to section 223(h) of the Act.