Pay structure will differ based on your work environment.
Most places will pay a flat rate regardless of experience. I make the same in my group as docs with 15+ years more experience. There's a bonus structure, but everyone still makes the same.
A friend of mine did start getting RVU bonuses after becoming board certified, but it doesn't go up any further.
Almost every CMG pays everyone the same, with the exception of some productivity differences. You might make $200/hr year one and $215 year two, but the difference isn't based on years of experience. Instead it's based on RVUs, billing, and patient numbers. In this model there is a theoretical cap where you can't physically bill any more.
Groups with partnership tracks typically pay significantly less during your pre-partner years. Say the partner rate is $200...you might make $150 as a "buy in". After the buy in period, you become partner and get that $200 rate. Depends on how long the buy in period is.
Other groups have multi-level partnerships. For example, the 5 docs who started the group are "partners" or owners with equity in the company and split the pie between themselves before it goes to the rest of the docs. I don't have real numbers, but say there's 50% net profit split between these 5 docs. After their cut, the remaining 15 junior "partner" docs split the other 50%. Of course any pre-partner docs don't get any profit share.
So, to answer your question OP: Yes. That's normal. Don't expect the rates to go up over time. In fact, if all this fear mongering about the new senate bill comes true, expect to get paid less. (scroll down the front page of sdn EM to read about that).
What can you do? If you want another sign on bonus, you can ask for a retention bonus. CMGs have an acquisition cost to hire a new doc, and it may be cheaper for them to pay you to stay. Or you can leave for another group and collect a different sign on bonus. Or you can join a SDG on a partnership track and make whatever their structure is. Or, you could get paid more through geographical arbitrage. Move to rural somewhere and make $400/hr if that exists.
But, you still won't necessarily make more over time. In fact, if you account for inflation, you'll make about 2-3% less year over year in real dollars.
This is a fairly simple explanation, though. I think there have been increases in average EM pay over the last decade, but I haven't seen anything built into current employment offers.
What I would do? Look into FI/RE. Be smart with your money, pay off your loans, and get to a point where your investments make enough money that your hourly pay loses some importance.
