A jury in October found Howard Stern and Dr Khristine Eroshevich guilty of conspiring to obtain prescription drugs for the former Playboy model by fraud.
Los Angeles judge Robert Perry ruled at a sentencing hearing he did not believe she was an addict under anti-drug laws.
Smith died in 2007 at 39 from a prescription drug overdose. The pair were not charged in her death.
"The court has no doubt that abuse of prescription medications is a troubling problem for many persons," Judge Perry said in his ruling.
"There is no doubt that there are doctors who are nothing more than pill pushers and should be prosecuted and imprisoned. This case did not involve such doctors."
He found that a 2006 California anti-drug law intended to curb prescription medication abuse recognised that "pseudo-addicts" seek drugs because they are in great pain.
He also found that although Mr Stern had used his own name and others to obtain painkillers for Smith, he did so to protect her privacy.
Dr Eroshevich had also been convicted of obtaining Vicodin by fraud in October, but Judge Perry reduced that conviction to a misdemeanour.
It's disgusting how much time and effort our society has wasted on Anna Nicole, living and dead.