You can refinance a jumbo loan, but you should expect more stringent underwriting standards compared to conforming and government-backed loans. Many lenders require jumbo loan borrowers to have a credit score of 660 or above and debt-to-income ratio at or below 43 percent. You may also be asked to show you have enough cash to make a couple of years' worth of house payments if necessary. If you’re struggling to make payments on a jumbo loan but can’t qualify for a refinance, ask your loan servicer about loan modifications.