is it worth to refinance again for 30 years from 4.625% to 3.375%?

From what you’ve said above, answer would be decidedly yes. Given sufficient equity, good credit, verifiable and sufficent income, and the expectation of being in your home for some time, it would certainly be in your best interest to scoop up a lower rate. One thing to consider would be looking at the rate options available versus the contribution your lender can pay for your closing costs. For instance, at 3.375%, you likely are paying all costs, possibly origination charge as well. While costs vary per state and lender, likely looking at minimum 2K (on the low side). By chosing rate of perhaps 3.5% or 3.625%, your lender might be able to pay either most or all those costs. I always try to cover whatever costs I can for borrowers…..if payment is $15 higher (for example) due to slightly higher rate, but closing costs are reduced by $1000, that’s a pretty darn good tradeoff. Let me know if you have any other questions!

Ted