HARP 2.0 permits borrowers to refinance with any mortgage servicer that participates in the program. Not all mortgage companies do. Second, banks have created their own rules to further narrow the pool of HARP applicants they'll accept. Today, Bank of America and Chase, for example, only accept HARP applications from their current mortgage customers. And some banks don't accept loans with LTVs over a certain amount, commonly 125 percent.
Call the lenders you're considering to ask if they're participating in HARP. Then, find out if you're able to refinance under their guidelines.