Final answer:
In a fee-for-service system, providers are reimbursed based on the cost of services they provide. In an HMO system, providers are reimbursed based on the number of patients they handle.
Step-by-step explanation:
The key difference between a fee-for-service healthcare system and a system based on health maintenance organizations (HMOs) is in the way medical care providers are reimbursed. In a fee-for-service system, providers are reimbursed based on the cost of services they provide.
On the other hand, in an HMO system, providers are reimbursed based on the number of patients they handle, and it is up to the providers to allocate resources between patients who receive more or fewer healthcare services.