The youth equivalent of England's top flight has been altered as a result of the Elite Player Performance Plan, with knockout rounds deciding the overall winner of a May finale
The league, and previous reserve equivalent, had been split into three separate groups and amended midway through the season depending on league standings.
But, following the introduction of the Professional Development League last season as part of the Elite Player Performance Plan, the Premier League has now altered the stages.
"There will be one national division, the Barclays Under-21 Premier League, comprised of 22 Category 1 Academies," read a statement from the Premier League.
"The Academies involved are: Arsenal, Aston Villa, Blackburn Rovers, Bolton Wanderers, Chelsea, Everton, Fulham, Leicester City, Liverpool, Manchester City, Manchester United, Middlesbrough, Newcastle United, Norwich City, Reading, Southampton, Stoke City, Sunderland, Tottenham hotspur, West Bromwich Albion, West Ham United and Wolverhampton Wanderers."
Clubs will play each opposing team in the league only once in a fixture either home or away, with at least three games being held at an outfit's main stadium.
The new changes will see all clubs compete in the national league before the top four teams progress to a knockout stage, with draws based upon league position, to compete for the winners' prize in May.