Snippet of Article: "...IRRRL stands for Interest Rate Reduction Refinancing Loan. You may see it referred to as a "Streamline" or a "VA to VA." Except when refinancing an existing VA guaranteed adjustable rate mortgage (ARM) to a fixed rate, it must result in a lower interest rate. When refinancing from an existing VA ARM loan to a fixed rate, the interest rate may increase.
No appraisal or credit underwriting package is required by VA. You should be aware, however, that lenders may require an appraisal and credit report anyway.
A certificate of eligibility is not required. Your lender may use our e-mail confirmation procedure for interest rate reduction refinance in lieu of a certificate of eligibility.
An IRRRL may be done with "no money out of pocket" by including all costs in the new loan or by making the new loan at an interest rate high enough to enable the lender to pay the costs. (Remember: The interest rate on the new loan must be lower than the rate on the old loan unless you refinance an ARM to a fixed rate mortgage). ..."
Article Source: www.benefits.va.gov