I don't doubt they do for Healthcare but for the billing system I dont think they are. They aren't going to your employer and saying Steve is fat so we're charging an extra $200 for him, but you can pass that on to him so the rest of your employees don't have to pay. In the end when they go to charge you and your employer they'll just give you the total rate to cover x people and then split it up by person.

Correct me if I'm wrong but the administrative overhead and health privacy implications would be too much to assess individual health cost liability.

Yeah they're going to keep track of every visit and procedure to make sure you aren't "overusing" your coverage and deny you if you do, but passing that un aggregated data over to the actuarys seems infeasible.