“Obvious and painless” but not inexpensive. If it were trivial to refinance, you’d effectively have a variable rate mortgage where the rates could only go down, not up.
That is more or less how I view my mortgage. I bought in 2007 at 6.5%, refinanced in 2011 to 4.25%, then again a few years later to 3.625%, and plan to refinance again soon if I can lock in a 2.75%, no-points sometime soon. There are no points, no closing costs refis available. The biggest hassle in refinancing is making copies/uploading 2 years of tax returns and whatever other paperwork the underwriters want.
It is inexpensive in the grand scheme of things, I recently refinanced and it cost around $2000, I’ll make that back in less than one year. If the cost of refinancing isn’t made back in a couple years maybe don’t refinance yet…
That’s exactly what it is, which is why the rate is higher than an actual variable rate mortgage (where rates can go up too).
If you deal with a small local bank, you may be able to get a portfolio mortgage that they hold, with some unique benefits. I recently did this, they matched the rate my existing lender (big international bank) gave me, plus they offer a float down on the rate once per 12 months for a fixed fee of $975. No refinance necessary.