Melissa Schuman accused Carter of raping her and waved her anonymity by writing a blog in February.
After being reviewed by prosecutors, the case was thrown out as the statute of limitations has passed.
Carter's lawyer Michael Holtz said he is "happy to put the matter behind him".
"Nick has denied these allegations ever since he first learned of them last year, and was confident the district attorney would conclude that there was no basis to pursue charges against him," Holtz said in a statement.
Schuman, 33, who was part of the teen girl band Dream, says she was 18 and a virgin at the time of the alleged attack, which she said took place after the pair recorded a duet.
She decided to come forward after seeing an allegation against Carter from another woman last year.
Carter, 38, feels vindicated that no charges will be brought against him, according to his lawyer.
The statute of limitations refers to a set timeframe when legal action must be taken for proceedings to take place, but in this case that timeframe had expired in 2013.
Prosecutors concluded that because of the amount of time that had passed, a proper analysis of strengths and weaknesses of evidence could not be achieved.
Schuman told the Associated Press that more should be done to accommodate retroactive assault claims.
She said she was "well aware of the likelihood that my case was not prosecutable", but that it had provided her with "great solace" to know that prosecutors had looked into her case.
"Speaking out was the best thing I could have ever done for myself," she said.
"I hope it inspires others to do the same if it feels right for them."