NO cost means all the refinance related cost will be cover, you only need to pay: 1. loan amount difference 2. inerests for both lenders 3. propoerty tax if still open 4. home insurance if need to be renewed other than those money ( which you always need to pay), all the rest cost such as credit score checking, appraisal fee, under writing fee, escrow fee , flood cert fee, tax certificate fee, reconveyance fee/forwarding fee, loan originaltion fee, processing fee, documetation fee, notary fee, recording fee....etc, will be fully covered to make it a truly no cost refinance. you can check my link to see how to calculate the agent rebate for no cost refinance: http://www.mitbbs.com/clubarticle1/BayAreaMortgageRate/11631_0_ Good luck