Winter, 14, who plays the brainy and precocious teenager Alex Dunphy on the Emmy-winning ABC comedy, will remain under temporary guardianship of her older sister, Shanelle Gray, under the settlement, court officials said.
Los Angeles Superior Court Judge Michael Levanas scheduled a hearing for March 29 in which he could hand permanent guardianship over to Gray and control of Winter's estate to her father, Glenn Workman.
Gray, 34, was first awarded temporary guardianship of the actress in October.
Winter's mother, Chrisoula Workman, has denied allegations, earlier submitted in court documents, that she verbally and physically abused her daughter.
Messages left with Winter's publicist and attorney seeking comment were not immediately returned.
"Modern Family" portrays the lives of three zany families and has won three consecutive Emmy awards as American television's best comedy series.