As often as you find helpful. A couple years ago, my rheumatologist had tried everything and nothing helped me, so our visits just turned into check-ins of how bad my pain was getting. So i stopped going. It was just wasting my money. So i haven't gone for a few years. Now I've found another one because i was having new issues. And then based on your symptoms your doctor will tell you how often could help

It depends on your rheumatologist, too. The rheumatologist I saw where I live now is the one who officially diagnosed me, but he basically said there was nothing else he personally could do for me.