Both abortion provider Planned Parenthood and the state Department of Justice had agreed on how the law ought to be interpreted, and Judge Richard Niess concurred. The law had been on hold since April 2013 while the case, which began in federal court but was moved to state court because of jurisdictional issues, was pending.
Niess said in his ruling that doctors have to be present when giving the drug to a woman, but they do not have to be there when the woman actually ingests the pill.
Republican Attorney General J.B. Van Hollen, who defended the law, said the ruling is in line with what his office always interpreted it to mean.
"No one ever tried to enforce the law differently," he said in a statement. "Planned Parenthood's case was a frivolous action from the beginning"
But Planned Parenthood attorney Lester Pines said the lawsuit was necessary to prevent anti-abortion district attorneys from going after doctors who distribute the pills but aren't present when they are ingested.
The Republican-controlled Legislature passed the law in 2012 and Gov. Scott Walker, an abortion opponent, signed it into law. Sen. Mary Lazich, a Republican who sponsored the bill, had no immediate comment on the ruling.
The law mandates that women having nonsurgical abortions visit the same doctor three times and that the doctor must ensure the woman is having the procedure voluntarily and without coercion. Failure to follow those requirements could result in felony charges against the doctor.
Niess said in his ruling that as long as doctors make good-faith efforts to determine that women seeking abortions were voluntarily consenting to the procedure, they can't face penalties if it turns out the woman had been coerced into getting an abortion.
Niess lifted the hold he put on the law last year and declined to issue an order permanently blocking the law.
The law bars Internet consultations, a practice used in other states but not Wisconsin.
The law does not affect emergency contraception, known as the morning-after pill.
Planned Parenthood initially stopped medical abortions at its clinics in Madison, Milwaukee and the Appleton area due to confusion over whether a doctor could be subject to criminal penalties if he or she is not present when the patient ingests the pill.
Those resumed when the law was put on hold last year and will continue, said Pines, the Planned Parenthood attorney.
"Planned Parenthood doctors are following the law," he said.
Teri Huyck, president and CEO of Planned Parenthood of Wisconsin, called the ruling a "victory for women and their ability to decide which medical procedure is best for their own health and circumstances."
"The decision recognizes that medical professionals should be trusted to determine the safest and best medical care for their patients," she said.
A separate lawsuit in federal court, also brought by Planned Parenthood, challenges a different state law requiring doctors performing abortions to have admitting privileges at nearby hospitals. The judge put that law on hold pending his ruling in a trial that ended in May.