Anderson has not played at any significant level for nine months after undergoing surgery in September to repair a stress fracture in his back.
He returned to action this month as a batsman only for the Northern Districts A side.
The 27-year-old, who once held the record for the fastest ODI hundred,
said he felt he had unfinished business in England ``and I hope I can help Somerset go all the way in 2018,'' he said in a statement.