Key is to do a good job representing the medical company and you should be safe. If you don't, just like being a direct employee, your job is in jeopardy. The length of the contract is immaterial as all contracts, no matter what CSO you are employed by, have out clauses. Just like if you were a direct employee of the medical company they can let you go. Bottom line, do your job well and your numbers should help you here or with future opportunities. If you just worry about the contract ending and don't focus on the work it will likely end because you are not doing your job...