5 years in, still at $180k. When do I push for more?

I've been at the same practice for 5 years. Started at $150k, got bumped to $180k after year 2, and haven't seen a raise since. I'm producing well over $1M annually for the practice. The owner keeps saying "we'll talk about it next quarter" but it never happens. I like the team and the patients, but I feel undervalued. At what point do I either demand a raise or start looking? I'm worried about burning bridges if I push too hard.