Is there a minimum amount of time between mortgage refinancing?

you should be able to refinance at anytime. Banks don’t mind because they collect the fees. Unless your financing has it in your agreement, you should be fine. Ask them about no points/no closing fees. If they don’t offer that, you can always shop other companies will wave those fees to get your business.

Just be aware of that each re-fi will affect your credit rating slightly (a couple of points here/there), as part of the credit inquiry/reporting process.

Also make sure you don’t have an early pay off penalty in your current loan. And the rates are going to go lower at least over the next 6 months. The recent rate cut was so deep that it may take 6–9 months for the rate to get as low as it will go.