The report says he would do this in the hopes of getting anti-doping officials to restore his eligibility and athletic career.
Armstrong was stripped of his seven Tour de France titles and barred for life from competing in all Olympic sports this past summer.
Yet Armstrong attorney Tim Herman denied that Armstrong has reached out to USADA chief executive Travis Tygart and David Howman, director general of the World Anti-Doping Agency.
Herman told The Associated Press he had no knowledge of Armstrong considering a confession and said "When, and if, Lance has something to say, there won't be any secret about it."
Armstrong, who retired last year, has consistently pointed to the hundreds of drug tests that he has passed as proof of his innocence.
The Associated Press contributed to this report.