If your home loan is serviced through Freddie Mac or Fannie Mae, the U.S. government requires your borrower to discuss loan modification with you and fully evaluate your financial situation to determine your eligibility–even if you’ve never missed a payment. … You don’t want to fall victim to a scam , but neither does your lender. Thus, it will want proof that your current financial situation does not permit you to continue making your mortgage payment each month. …

The rest is here:
Five Tips for a Successful Mortgage Loan Modification