The obligation to repay Medicare is the beneficiary/plaintiff's obligation. Medicare has a lien against all recoveries that a beneficiary has obtained where Medicare has made "conditional payments" for the medical bills incurred for treatment needed for the injuries suffered in the incident. So, yes, it sounds to me that Medicare's lien touches the recoveries received from all defendants in your case,
What gets disbursed depends on the terms of the settlement agreements and the law. At a minimum your attorney would need to hold back enough money to pay the Medicare lien until Medicare presents a Final Demand Letter, and then pays that net demand.
Speak to your attorney about what he must hold back and what can be disbursed.
BISNAR|CHASE, Personal Injury Attorneys.