34 C.F.R. § 681.12
(a) After the repayment period has commenced, installments of principal and interest need not be paid during any period:
(b) For any HEAL loan received on or after October 22, 1985, after the repayment period has commenced, installments of principal and interest need not be paid during any period for up to 2 years during which the borrower is a participant in:
(1) A fellowship training program, which:
(2) A full-time educational activity at an institution defined by section 435(b) of the HEA which:
(c)
(2) For those activities described in paragraphs (b)(1) or (b)(2) of this section, the borrower may request that the Secretary review a decision by the lender or holder denying the deferment by sending to the Secretary copies of the application for deferment and the lender's or holder's denial of the request. However, if information submitted to the lender or holder conflicts with other information available to the lender or holder, to indicate that the borrower fails to meet the requirements for deferment, the borrower may not request a review until such conflicts have been resolved. During the review process, the lender or holder must comply with any requests for information made by the Secretary. If the Secretary determines that the fellowship or educational activity is eligible for deferment and so notifies the lender or holder, the lender or holder must approve the deferment.
(Approved by the Office of Management and Budget under control numbers 1845-0125 and 1845-0128)