It's a lot higher than 100k. And benefits-what benefits? We have to pay our own health insurance, like 60 or 100 something bucks per check. We also have to pay parking AND food! So what benefits? Chief residents normally are given like 1k stipend, that's it, and they are typically in their final year so I think your statement is incorrect. My chief is simply the 5th year resident.
And residents make tons of $$ for the hospital, bc if there were no residents programs would have to pay attendings $$ to take care of patients, which would cost them a lot more.
There's something like $9.6 billion total subsidy from Medicare that funds ~100k total residents. If you take into account all the subsidies (medicaid, state funding, VA money), you're still only getting about $13 billion. And there's something like ~112k total residents (many are not medicare funded). That's not counting the fellows either. Even if you stretch it quite a bit, you don't get to much more than $120-130k or so total subsidy per resident. And really, it's probably a fair bit closer to $100k than $150k. I'd love to see a citation saying otherwise. (Note that some programs get quite a bit less money per resident than others. Two thirds of medicare subsidy is "indirect" medical education funding, and that's not distributed equally. I don't know the specifics of how that formula is put together, but I know it's complicated.)
For the other points, if you think your $60/check covers your health insurance premium, I want some of what you're smoking. Not to mention it sounds like you're at a crappier program, because quite a few of them have much better benefits than that. Out of the 17 programs I interviewed at last year, 15 completely and totally paid for parking. Almost all of them had at least some kind of food subsidy, with a few hospitals basically providing up to almost $10,000 worth of food per resident per year (if you took advantage of the daily food budget). A large portion of them covered at least the cheaper plan for individual healthcare benefits in total, including my own. Trust me, if you add up even just the health/vision/dental/disability/life insurances, not to mention the employer portion of payroll taxes, you'd end up with AT LEAST $15k worth of benefits per resident per year. That's not counting the stuff like food.
You skipped right past all the (required by the ACGME) salary subsidies and nitpicked regarding chief residents. I meant in particular the chief residents in specialties like Medicine and Pediatrics, where they stay on an extra year as junior faculty members in administrative roles. Their salary needs to be paid for by the program. Mind you, that's chump change compared to all the program directors and administrators and such, but it is an expense.
As for whether residents make money for the programs, this is very controversial. A typical resident team in medicine handles ~15-20 patients. For that, you will frequently have 2 interns, a senior resident, and an attending. Mind you, the wards attendings will often have some other duties as well (administrative stuff, clinics, whatever), but that's still quite a bit of pay for the team. On the other hand, a hospitalist can see 15-20 patients alone with only one salary being paid. That hospitalist is a lot more confident in their care, and might get patients out with a lower length of stay and use less diagnostic tests. Depending on the insurance of the patient, that may actually get the hospital MORE money by using less diagnostic tests (if there's a global payment for a diagnosis related group, the hospital gets paid per visit, not piecemeal). As someone in a 5 year specialty (I presume something surgical), your patients are almost certainly getting the hospital money based on global payments. If you keep them a day longer than they would be kept in the community, that's costing the hospital (not the program) significant cash.
You can see a similar pattern in many specialties. A surgeon can most certainly do the procedure on their own (+/- a PA or other individual trained to primarily first assist) faster than walking the resident through it. Is the resident cheaper than a PA? Sure. But if the surgeon could conceivably fit an extra operation in each day, that more than wipes out the difference. Is it easier to be an academician when you have residents to do a lot of your scut? Yes. But they take lower pay for that "ease". Some of the difference in pay actually subsidizes the educational program (or so the claim goes).
I don't honestly know who's right. Maybe MedPAC is and the subsidies are too large and hospitals just pocket the difference. Maybe the hospitals are right and we overall cost them money. But you can't legitimately say the only expense in training residents is our actual salaries, that's utter nonsense.
Edit: Oh, and the malpractice insurance mentioned at the following post is a huge point. That's a major expense that probably chews up a fair bit of the subsidy.