OTAs consist of 10 voluntary days over the next three weeks. It is not known yet whether Beckham plans to participate in all 10 practices. The Pro Bowl wide receiver took part in seven of the New York Giants' 10 last year.
The Browns also have a three-day mandatory minicamp in June.
Cleveland acquired Beckham this offseason as a weapon for quarterback Baker Mayfield, the No. 1 draft pick in 2018 who led the Browns to a 7-8-1 mark last season after the team went 0-16 the year before.
After his introductory news conference in early April, Beckham left for vacation, to work out in California and to attend to personal business.
New Browns coach Freddie Kitchens defended Beckham's decision to miss voluntary practices, saying he was in constant touch with the 26-year-old and confident he would be "ready to play.''
The Associated Press contributed to this report.