From The NFL:
As per Article 21 of the Collective Bargaining Agreement, each club’s official, voluntary nine-week offseason program is conducted in three phases:
Phase One (4/21-5/4) consists of the first two weeks of the program with activities limited to strength and conditioning and physical rehabilitation only.
Phase Two (5/5-5/26) consists of the next three weeks of the program. On-field workouts may include individual player instruction and drills as well as team practice conducted on a “separates” basis. No live contact or team offense vs. team defense drills are permitted.
Phase Three (May 28-30, June 2-3, June 5, June 9-10,June 12-13) consists of the next four weeks of the program. Teams may conduct a total of 10 days of organized team practice activity, or “OTAs”. No live contact is permitted, but 7-on-7, 9-on-7, and 11-on-11 drills are permitted.
Mandatory minicamp will be held from June 17-19.