There are four major groups of physicians:
-Residents. These are the folks that just completed medical school, and are doing four-plus years of training in a hospital setting to become independently practicing physicians. In year one they are called interns. By year three or four they have various amounts of independence: in internal medicine, family medicine, etc. they are basically practicing as full physicians, with some light supervision (the heavy supervision is years one and two). They are one of the hospitals most valuable employees: taking into account supervision costs, they are producing about 80-90% of the revenue of a "real" physician, for less than 1/4 the cost. These are the guys who work 80+ hours per week without exception, do all the scut, etc. These are not "mid career physicians". This is where "old physicians had to go through it, so young physicians have to go through it."
--Resident Training: the AMA has been pushing to expand resident training spots for years. The funding is part of Medicare legislation, and no one has been willing to back expanding medicare spending in the name of training physicians. I know the AMA has been backing this because I've attended the Region 7 and national meetings where the resolution to push for it has been passed, repeatedly. Literally, hit DDG and enter "AMA restricted residency training funding" and your entire page of results is the opposite. They may have done so more than a generation ago, but... let's move onto things that were done by, and affect, people not currently retired, eh?
-Hospitalists. These guys have completed their residency training, and elected to work for a hospital, doing in-hospital medicine. Their specialty is "hospital medicine." They have no private clinic, no private patients, and are paid a salary by the hospital. Whether this is an integrated system like Kaiser, or ... every other hospital in the market, they're very common. Their practice patterns are heavily dictated by the hospital, which is heavily dictated by the Centers for Medicare/Medicaid Services and the major insurers. Their work is increasingly focused strictly on documentation, since documentation is the way that CMS and insurers (a) find excuses to refuse reimbursement, and (b) the way that CMS and insurers outsource collection of "quality" information, by forcing docs to structure their input in very discrete ways. These physicians don't have to deal with billing directly, but they are constantly being pulled into trainings for the ways documentation requirements are constantly evolving, the ways in which payors want them order tests and in what order, etc. They constantly get phone calls from "helpful billing people" raking them over the coals whenever there's a mistake. THe hospital keeps running tallies and reports on doctors' mistakes in this arena, aiming for public pillorying and, ultimately, withheld wages. (Docs don't generally get bonuses, they get withheld wages - except for high-revenue services like procedures, where they may get a bonus for very high productivity.) These are "mid career physicians." They tend to work an official 10-12 hour day, ten days on, ten days off. In reality, due to documentation requirements, and the fact that they get more patients than anyone could ever see and document in 10-12 hours, they tend to work 14+.
-Private Practice. These guys completed their residency and either opened their own private practice (almost no one can do that these days, with the complexity of the documentation and EMRs required by CMS and insurers, and attendant overhead costs) or have become employed by such a practice with the medium-term goal of buying in as a partner. They are likewise having their arms heavily twisted by insurers and CMS, without any sort of leverage to fight back and negotiate better terms. These guys are going out of business left and right. These are "mid career physicians." Hours worked here are highly variable, depending on the specific practice pattern, number of employees and partners, etc.
-"Private Practice." Because of the complexities and overhead that are now required to stay open, many practices... can't. They sell to a local hospital - often at cost - and become hospital employees. The hospital offers solid salaries for the first couple of years, and then drives them out, replacing them with younger employees. Many of the "private practices" you go to are thus actually practices run by the hospital, with an employee acting as the physician. These are "mid career physicians." These tend to work 9-5 with one evening hour a week, or none. The spread of this is why no one can find a doctor to see in the evenings anymore.
Key to Understanding Medical Reimbursement:
This is not a free market. It is fee for service. You get a patient visit, it is coded as a particular service (usually a Level 3 Evaluation & Management), and a fixed amount of reimbursed, assuming you meet various documentation requirements. If you do not, the amount is decreased or denied altogether. Private insurers peg their fee schedules to CMS, so CMS - directly or indirectly - drives all physician reimbursement. If you own a geographic area (such as part of a sweeping hospital network), that network will negotiate better reimbursement (e.g., "112% of Medicare"), but that is not passed along to employee physicians. Total revenue for a physician is amount of work-time per year divided by time-per-average-service, times reimbursement-per-average-service.
That's it; that's your cap.
Thus, most services patients want are strictly cost centers. The sort of things that other businesses compete on - e.g., ambiance, good front desk staff - are problematic for physicians, because you can't pass that along to patients in moderately higher prices. The only way you can compete on service, and be free to set your prices accordingly, is to refuse all insurance and only take cash patients. There are vanishingly few such patients, largely due to a cultural expectation that insurance = healthcare. Actually paying cash for a primary care physician, at least, isn't that expensive, but since that doesn't cover all of your other healthcare costs, who can afford to pay that extra premium? Only upper-middle-class and up.