Assumption of SBA Loan. Assumption of Loan Requirement Letter for disaster loan servicing action request packages.About this document and download. Create an account in the MySBA Loan Portal (lending.sba. Gov) to monitor your loan status or to make payments. SBA loans are fully assumable with SBA approval. Getting this approval, however, can be very complex. Proof of ongoing insurance on the collateral with the SBA named as mortgagee must be provided. An assumable mortgage involves one borrower taking over, or assuming, another borrower's existing home loan. Find out how it works.