Multifamily Loans October 18, 2018 203(b) Loans, FHA 203b Loan Assumption in Relation to FHA 203b Loans Multifamily Loans October 18, 2018 203(b) Loans, FHA 203b Loan assumption occurs when the buyer of a property takes on, or ‘assumes’ the existing mortgage on the property. While most conventional home loans are not assumable, FHA 203(b) loans are— and that’s a big benefit for borrowers.