But Attorney General Ken Cuccinelli, who launched the challenge, conceded in a statement the battle is far from over, The Washington Post reported.
"I am gratified we prevailed. This won't be the final round," he said, "as this will ultimately be decided by the (U.S.) Supreme Court, but today is a critical milestone in the protection of the Constitution."
The U.S. District Judge Henry Hudson in Richmond ruled Congress exceeded its authority by requiring all Americans to have at least minimum health insurance or pay a fine, though he upheld the rest of the law and said he would not try to prevent the law from being implemented. A separate ruling in Virginia by another federal judge last month ruled the opposite way on the individual requirement.
And Cuccinelli's challenge is one of a group making their way through the courts nationally and having varying degrees of success.
U.S. Justice Department spokeswoman Tracy Shmaler said in a statement, "We are disappointed in today's ruling but continue to believe -- as other federal courts in Virginia and Michigan have found -- that the Affordable Care Act is constitutional," the Post reported. "There is clear and well-established legal precedent that Congress acted within its constitutional authority in passing this law, and we are confident that we will ultimately prevail."
White House spokesman Robert Gibbs pointed to the favorable rulings, and said, "We are confident that (the individual mandate) is constitutional."
The conservative American Center for Law and Justice chief counsel, Jay Sekulow, said in a statement: "We're very pleased the federal court reached a sound decision and concluded that the individual insurance mandate is an unconstitutional violation of the Commerce Clause. This decision guts ObamaCare and represents a decisive and significant victory for America against the largest power-grab by the federal government in U.S. history. The court correctly concluded that forcing someone to buy health insurance is not economic activity and Congress does not have that authority under the Commerce Clause."
Mark R. Levin, president of the conservative Landmark Legal Foundation, said in a statement the judge's "ruling against the Obama administration and for the Commonwealth of Virginia gives hope that the rule of law and the Constitution itself still have meaning. ... It is a great day for the rule of law and the citizenry. Judge Hudson's ruling is ironclad, and General Cuccinelli deserves an enormous amount of credit for taking on this matter."