named Bay as the Interim U.S. Attorney in New Mexico on March 8, 2000. At the time Bay was named Interim U.S. Attorney, he was a supervisor in the U.S. Attorney's Office in New Mexico and had been an Assistant U.S. Attorney for more than a decade. President Bill Clinton nominated Bay to the Senate on May 25, 2000, and the Senate unanimously confirmed Bay on September 8, 2000. As United States Attorney in New Mexico, Bay inherited the Wen Ho Lee case, which had been charged before Bay took office. This case involved a Chinese-American scientist accused of mishandling nuclear secrets. Six months after Bay became Interim U.S. Attorney, the case was resolved through a plea agreement. At the hearing, Judge James Parker criticized other top government officials but called Bay an "outstanding" member of the Bar whom he held in the "highest regard." After his successor, David Iglesias, was confirmed by the Senate, Bay resigned as U.S. Attorney on October 15, 2001.
In 2009, Bay became the Director of Enforcement at the Federal Energy Regulatory Commission in Washington, D.C. According to Reuters in 2012, "FERC’s Office of Enforcement, run by Norman Bay, has stepped up its game lately, taking the lead among regulators in cracking down on trades that cross both physical and financial markets." In 2013, an energy trade journal named Bay as one of the top ten most influential people in energy. Harvard Professor William Hogan expressed concern about FERC's Office of Enforcement's practices. Hogan said the Office's practices were "alarming" and could "unravel" the power markets. In its case against FERC, Deutsche Bank stated that FERC's views were "radical," though it later settled the case for nearly $1.7 million, including over $170,000 in "unjust profits" without admitting or denying wrongdoing. J.P. Morgan paid $410 million to settle the FERC investigation without admitting wrongdoing. J.P. Morgan stated "We strongly dispute that Blythe Masters or any employee lied or acted inappropriately in this matter." On January 30, 2014, Bay was nominated by President Barack Obama as Commissioner of the Federal Energy Regulatory Commission, and upon appointment to be made Chairman of the Commission. On May 20, 2014, Bay appeared before the Senate Energy and Natural Resources Committee for his confirmation hearing. Bay was introduced by former Republican Senate Energy and Natural Resources Chairman Pete Domenici and Senate Energy Committee member Martin Heinrich. The former Energy Chairman testified, "The job that he is seeking demands somebody just like him," Domenici said. "And obviously I would urge that this Committee support him. "I'm not a great fan of the President of the United States and people know that, but I think this is a great appointment. So I am on his side on this. I don't see how you can miss." On June 18, 2014, the Committee approved Bay to lead FERC and he was voted out of committee 13-9. He was subsequently confirmed by the Senate 52-45 on July 15, 2014. Under his tenure, FERC moved up in rankings based on the Federal Employee Viewpoint Survey, and FERC was the highest rated mid-sized agency in 2017. Bay resigned from FERC in January 2017.