He explains to Cate Banfield that he is relocating to Chicago, and is looking to pick up some shifts.
She agrees, after finding out that one of his teachers at the hospital was Mark Greene. At the end of the episode, it is shown that Carter is on dialysis because of amyloidosis developing from schistosomiasis which irreparably damaged Carter's remaining kidney.
He cited a budding family and an already lengthy tenure on the show as reasons.
When the clinic is overrun by a militia, Carter is threatened by guerrilla soldiers. When Kovač is reported killed in Africa, Carter goes back to retrieve his body but finds Kovač ill with malaria.
Kem's pregnancy ends tragically at eight months forcing her to give birth to a stillborn son in the episode "Midnight", much to her and Carter's overwhelming grief.
He is supported emotionally by his father and by his friends Luka Kovač and Abby Lockhart. During Season 11, Carter starts building an HIV/AIDS clinic adjacent to County General, with funding from his family's charity foundation.
These personal issues come to a head when Abby's bipolar brother Eric reappears the day Gamma dies.
Abby giving precedence to her duty as a sister marks the beginning of the end of Carter and Abby's relationship.
In order for Carter to change from his surgical residency to an emergency medicine residency, he agrees to work for free.