<prompt> Human: My dad currently has a 425k mortgage 3.80 and a 75k 2nd lien mortgage 4.5. Currently he is making 3,500 payments per month on both, combined despite the fact that his required combined payment per month is something like 2,750Hes been offered the opportunity to refinance into a jumbo mortage - 20 Yr a fixed 3.33 rate. Payments would be 2,800...with minimal closing costs its obviously a pure good to take this opportunity to refinance.Heres where things get interesting...he could also refinance into a 15 Yr a fix 3.0 rate! Payments would be 3,500, which is what he is paying now, but he would be locked into making these payments for the next 15 years.Being locked into such a high payment for 15 years makes him pretty nervous, even if hes already making it work now. He in a high-level sales position, so his compensation is partially based on a bonus if I had to guess, 25 or so of his comp is a bonus.Here is my take: the interest savings on the 15-year are hard to pass up. My dad has 150k in his 401-k that he will be able to access in a 4 years I believe they have other retirement money in the form of pensions...that said they havent done a great job of saving for retirement. My sense is that gaining access to these funds is a sort of security that should give my dad comfort that he can continue to make these 3,500 payments...if something bad were to happen in a few years he could always start supplementing his payments with regular withdraws from his 401k.To summarize1. They will benefit from the financial discipline to keep making large monthly payments they need this2. Material interest savings with the 15 year3. My dad has the 401k payments as security should anything go wrong4. They could always refinance into a 20 year, but rates could go up...this the primary riskAm I thinking about this correctly? Anything Im missing? Thanks for any feedback!  <response>: Facts: Hes retiring in 4 years assuming, based on the 401k date He hasnt done a great job saving for retirement A 3500 mortgage makes him nervous He can pay 700 less and still drop his rate by greater than 1Sounds to me like the 20 year mortgage, combined with overpaying while hes still sure hes able to, is the way to go. 