Is Medicare fraud really a meaningful amount compared to how much it pays out? Europeans have had the same issue for decades, you can’t give things away without some grifting. But that’s part of the cost. Usually not a very large one either.

Just a quick looks suggests it is a big issue. Hard to get firm estimates (presumably because we only know about the people who get caught) but one estimate has it at 7% of total expenditures of $700 billion which puts it at around $49 billion / year.

https://safeatlast.co/blog/medicare-fraud-statistics/

which is less than the fraud in private insurance industry, which is 10%.

https://www.propublica.org/article/we-asked-prosecutors-if-h...

How does Germany do it?

In Germany it's reverse. In the typical case the waiter verbally abuses the paying customer. Like when are not friendly enough to the waiter. Or you only can pay with credit card