you are right, but the doctors tend to raise their prices every year by the same amount. Medicaid or no Medicaid. at least that is what I think is happening.
Most companies raise their prices by about 3% due to that being considered the standard increase in cost of living per year.
However, if this is what you are thinking is raising medical costs, I don't buy it.
Medical Insurance rates raise way more than 3% a year. Why is that? It's due to liability. Doctors have to be greatly insured against lawsuits. The cost of their insurance and operating expenses raise more than 3% a year. They also have to perform unneeded tests on people to rule out everything prior to diagnosis. If they don't, they risk getting their butt sued.
Medicare/Medicaid does play a roll in determining the going rate for services, but it is not as you would think. They are the baseline that insurance companies look at to determine what they will cover and what the going rate should be. Some pay more than that with their insurance, but not a lot pay less.
Most of the time, however, Dr's rates are higher than what they except through different insurances or through Medicare/Medicaid, so they hardly ever get paid their actual rate. Medicare/Medicaid may have played a roll in the beginning of the raising insurance rates, but it is very doubtful that they are a big player in it now.