Not in Germany, they don't. Barmer is a "gesetzliche Krankenkasse"/public insurance, which means most of their members' premiums are legally limited to a certain percentage of their members' income, and while they can and do raise their premiums occasionally, that's always a topic of political debate and needs a better justification than "a very small percentage of our members need expensive exo-skeletons now."
They have no ability to raise premiums on specific members with high healthcare costs.
There's more to the world than the parochial ways of central north america so such locale specific observations deserve to be qualified for the benefit of the wider HN readership.
They have no ability to raise premiums on specific members with high healthcare costs.