Assistant Secretary for Financial Institutions Michael S. Barr Written Testimony on Stabilizing the Housing Market before the House Financial Services Committee, Subcommittee on Housing and Community Opportunity

… I want to highlight some key points of success:

We have signed contracts with over 45 servicers, including the five largest. Between loans covered by these servicers and loans owned or guaranteed by the GSEs, more than 85 percent of all mortgage loans in the country are now covered by the program.

Over 570,000 trial modifications have been offered under the program. Over 360,000 trial modifications are underway.
…
[W]e recognize that any modification program seeking to avoid preventable foreclosures has limits, HAMP included. Even before the current crisis, when home prices were climbing, there were still many hundreds of thousands of foreclosures. Therefore, even if HAMP is a total success, we should still expect millions of foreclosures, as President Obama noted when he launched the program in February.

Some of these foreclosures will result from borrowers who, as investors, do not qualify for the program. Others will occur because borrowers do not respond to our outreach. Still others will be the product of borrowers who bought homes well beyond what they could afford and so would be unable to make the monthly payment even on a modified loan.
It is that third category that is key – that is all the homeowners far underwater who bought homes they could never really afford.