Moss left The Meadows clinic outside Phoenix earlier this week and was spending time with friends in the United States, according to a statement released by the London-based Storm agency.
"Kate is in excellent spirits and looking forward to getting back to work. She would like to thank everyone for their messages of support as they have played a major part in helping her," a Storm spokesman was quoted as saying.
The 31-year-old supermodel entered the clinic after photos of her apparently snorting cocaine in a London music studio were published last month in the Daily Mirror tabloid.
The Storm agency said Moss would be working on modeling assignments in Los Angeles, Paris and New York in the next month.
She has lost contracts with H&M, Burberry and Chanel.
H&M announced this week that Italian model Mariacarla Boscono is replacing Moss in TV commercials to help launch a new collection by Stella McCartney next month.
Moss, who began modeling at 14, issued a statement after the photos were published saying she was addressing her problems and took "full responsibility" for her actions.