It's the latest chapter in a 19-year-old dispute brought by poor school districts in five counties.
The court ruled in 2004 that the constitutional right to a sound, basic education includes helping young children at risk of falling behind their peers. Legislative leaders then committed to a program of pre-kindergarten services.
But in 2011, new Republican majorities in the General Assembly effectively limited the program by restricting the number of slots for at-risk 4-year-olds and cutting funding by 20 percent.
The districts took legal action. But while the case was pending, lawmakers made changes the Supreme Court now says make the controversy moot.
Lawyers for the state had argued that a court mandate that North Carolina provide pre-K to all four year olds is flawed because the original case only applied to Hoke County.