Okla. Admin. Code § 330:15-3-7
Program provisions for assumption of mortgage loans, or that loans are due on sale, for mortgages under each Program shall be set as the Trustees may determine to be necessary under the market conditions prevalent at the time the Program is being developed and as may be determined by the Trustees in their discretion at the time of finalization of the Program . A Program may be changed after the commencement of a Program to provide for assumption of mortgage loans where the Program did not allow for assumption, provided that all necessary parties agree to such change, opinion of bond counsel advising of such changes is not in violation of the bond indenture of the Program , and that all necessary steps are taken as may be necessary to amend the Program Documents . In all Programs providing for assumptions of mortgage loans, all assuming parties must qualify as a borrower under the terms and conditions of the Program in question, except that if the Program is intended to be tax-exempt under the Code, then the qualifications of the assuming borrower must be sufficient to at least satisfy the requirements of the Code in regard to such assumption.
Okla. Admin. Code § 330:15-3-7