"The UCI today announced that exceptionally there are 19 registered UCI ProTeams in the 2013 season," the International Cycling Union (UCI) said in a statement on Monday.
"The decision to have 19 as opposed to 18 teams was taken by the Professional Cycling Council today."
Katusha, who finished second in the world standings last year, appealed to CAS in December after the UCI rejected their application to compete in the top flight because of the team's doping record over the past four years.
CAS upheld the appeal last Friday.
ProTour teams are automatically granted a start in the top races of the season, including the grand Tours and the most prestigious classics.