Immelt earned his M.B.A. from Harvard Business School, graduating in 1982. He described business school as “one of the most intense times of your life.”

Immelt had been with GE since 1982, when he graduated from Harvard with a Master of Business Administration degree. He held a number of increasingly senior positions in GE’s plastics, appliances, and healthcare businesses. He became a GE officer in 1989, joined the GE Capital board in 1997 and took on the leadership of GE Healthcare before being named CEO.

The competition for the CEO position that Immelt won began when Jack Welch asked Gary Wendt, the head of GE Financial Services, Inc, then a $41 billion empire and GE’s most profitable division, to resign, on the theory that he would overshadow Welch’s other candidates. Immelt surpassed Robert Nardelli, who was so close to Welch that his nickname was “Little Jack”, and James McNerney; Nardelli would leave GE to head Home Depot and then Chrysler, and McNerney left GE to lead 3M (before going on to lead Boeing). Immelt was selected by the GE Board in November, 2000, to succeed Welch as CEO of GE; he served as GE’s president and chairman-elect for ten months before taking the position of chairman and CEO of GE on September 7, 2001. He retired, three months earlier than expected, as chairman of GE’s board on October 2, 2017. He also concurrently stepped down from the board of Baker Hughes.

His tenure as chairman and CEO started off on a low note, as he took over the role on September 7, 2001, just four days before the terrorist attacks on the United States, which killed two employees and cost GE’s insurance business $600 million, as well as having a direct effect on the company’s Aircraft Engines sector.

Immelt defended GE’s reporting elections and the quality of its financial statements following heightened scrutiny after the Enron crisis. In 2001, his first year end as CEO, Immelt famously offered the market and the SEC a choice in financial reports, a new dramatically expanded set of reports with more details, versus what had been the traditional format for GE’s SEC filings. The experiment seemed to confirm that the traditional format, which was shorter, was preferable and it continues to be used at GE today. Immelt’s intuition and judgments about financial reporting transparency were validated in experiments in behavioral economics conducted at Princeton in 2004. Immelt has led GE through two reporting challenges since then: it has been required to restate its SEC filings; and, in 2009 GE agreed to pay the SEC $50 million to settle allegations of accounting fraud.

On March 3, 2002, according to its fiscal 2001 SEC Form 10K GE had 9,935,629,691 shares of voting common stock outstanding with an aggregate market value $396.1 billion on March 2, 2002. On January 31, 2015, according to its fiscal 2004 SEC Form 10K, GE had 10,064,909,484 shares of voting common stock outstanding with an aggregate market value of at least $261.1 billion on “the last business day of [Ge’s] most recently completed second fiscal quarter.”

Jeff Immelt has earned significant honors throughout his career, beginning with his graduation from Dartmouth cum laude and earning the Earl Hamilton Varsity Award, as a college football player, for friendship and character. Later in 2002, he received the Robert Fletcher Award from Dartmouth’s Thayer School of Engineering.

On February 26, 2002, shortly after becoming GE’s chairman and CEO, Immelt gave a Town Hall speech at Georgia Institute of Technology as a guest of their president. In the years that followed, Immelt gave the commencement address at Northeastern University (2006) and received the honorary Doctorate of Business Administration. He returned to Georgia Tech in the spring of 2007 as their commencement speaker. He was commencement speaker at the University of Notre Dame on May 20, 2007, where he was awarded the honorary Doctor of Laws. He was commencement speaker at the Worcester Polytechnic Institute on May 17, 2008 and received an honorary degree.

Barron’s has named Immelt one of the “World’s Best CEOs” three times. He is a member of The American Academy of Arts & Sciences. The Financial Times named him “Man of the Year” in 2003. Immelt was named to Time magazine’s 100 most influential people in the world in 2009.

Immelt initiated one of his first major acquisitions in his area of operating expertise, the medical business. In 2004 GE bought UK based Amersham PLC for $9.5 billion. GE is currently attempting to complete its acquisition of Alstom, France businesses for an enterprise value of $13.5 billion

After becoming chairman of GE, Immelt delivered his first university address to the 2001 graduating class of the Thayer School of Engineering at Dartmouth College, of which he is an alumnus, as their Investiture Speaker. He gave the college commencement address and received an honorary Doctor of Laws from Dartmouth, in June 2004.

Immelt served as chairman of The Business Council, a nonpartisan organization, in 2005 and 2006. It is notable that two other GE CEOs, Reginald Jones and Jack Welch, also served in this capacity.

Immelt was named a member of the board of the Federal Reserve Bank of New York in 2006. He resigned the board position in 2011.

The GE plastics business was sold in 2007 for $11.6 billion to Saudi Arabian interests. Welch had been the leader of GE’s plastics business before being named its overall CEO. In 2014 GE agreed to sell its appliance business for $3.3 billion In 2013 Immelt completed the sale of NBC Universal to Comcast for $8 billion.

Immelt’s compensation has fluctuated significantly. As CEO of General Electric in 2007, Immelt earned a total compensation of $14,209,267. In 2008, he earned a total compensation of $5,717,469. In 2009, Immelt earned a total compensation of $5,487,155. In 2010, Immelt’s compensation nearly tripled to $15.2 million. Immelt had a total five year compensation of $53.82 million through 2011, an income which ranked sixth among executives employed by US-based conglomerates. Some components of his total compensation package over the years have been newsworthy. In some years he was granted stock options at $0, and in other years he was paid no bonus. In 2014 his compensation totalled $18.8 million, a decrease from his 2013 compensation of $25.8 million. That 2013 compensation had risen 20% over his 2012 compensation of $20.6 million.

He was elected a Charter Trustee of his alma mater, Dartmouth, in 2008 and as of 2015 continues in that role. He has also served Dartmouth on its Alumni Council and as a class officer.

The GE Foundation has been extolled as a leader in corporate charitable giving since Immelt became GE CEO, with special attention to its efforts to support schools in the US, over and above its university activities, and healthcare in poor countries. Under Immelt, GE frequently appears in lists of notably charitable US corporations; for example, GE was pictured No. 8 in 2008 with charitable disbursements of $161.5 million in a ranking published by Forbes.

In February 2009, in the early days of the Obama administration, Immelt was appointed as a member to the President’s Economic Recovery Advisory Board to provide the president and his administration with advice and counsel in fixing America’s economic downturn. When President Obama chose to put Jeffrey Immelt at the head of the Economic Advisory Board, he felt that Immelt had attributions in knowing what would help the global economy. Obama has reported that Immelt has emerged as one of his top economic advisors in regards to trying to rebuild America’s economy.

In 2009, Immelt won the Oslo Business for Peace Award, an award chosen by winners of the Nobel Prizes in Economics and Peace and given to leaders in the private sector who have demonstrated transformative and positive change through ethical business practices.

General Electric year end employment has varied from 273,000 in 2010 to 305,000 in 2014, a net increase of 37,000. Employment had dropped from 315,000 in 2002 to 307,000 in 2013.

During the US Presidential election of 2012, GE came under attack for not paying US federal taxes while receiving substantial federal tax benefits. While the tax attacks created the impression that GE paid no taxes, its worldwide tax expense was over $3 billion, with most of the taxes paid in foreign jurisdictions. GE is reported to have paid no federal US taxes in 2010.

Immelt served as commencement speaker at Michigan State University’s 2 pm ceremony on December 11, 2010, and was awarded an honorary doctorate of business. He was the commencement speaker on May 23, 2010, at Hamilton College, which awarded him its honorary Doctor of Laws, and on May 24, 2010, at Boston College, where he was awarded the Honorary Doctor of Business Administration. He addressed the undergraduate class of 2011 of the University of Maryland, Baltimore County on May 23, 2011, and received an honorary Doctor of Public Service degree despite controversy at the school over GE’s corporate tax strategies. In May 2013, he delivered the commencement address at the University of Connecticut Graduate School, and was awarded an honorary Doctor of Humane Letters. In 2015 he delivered the commencement address at Siena College where he was also awarded the honorary Doctor of Humanities.

Immelt’s reorganization of GE has been accomplished in part through a number of acquisitions. He underscored the riskiness of an acquisition-based growth strategy in 2011 when he said, “You can’t do a lot of deals, and have them all be great.” Geographically his strategy has focused on two areas: China and Europe.

GE’s efforts in China have been central to Immelt’s vision. In July 2011 Immelt’s General Electric announced that it is in the process of relocating its X-ray division from Wisconsin to China. Immelt had previously referred to China as GE’s “second home market”.

On January 21, 2011, President Obama announced Immelt’s appointment as chairman of his outside panel of economic advisers, succeeding former Federal Reserve chairman Paul Volcker. The New York Times reported that Obama’s appointment of Immelt was “another strong signal that he intends to make the White House more business-friendly.” The council met a total of four times, with its final meeting on January 17, 2012. In 2013, the authorization for the council was not renewed, causing the council to be permanently shut down.

In April 2015, GE announced a major series of reorganization steps. It plans to sell its real estate business for $26.5 billion, sell most of its GE Capital assets which now total $500 billion, and repatriate nearly $36 billion in cash held overseas to fund while the board also authorized a share buyback program using up to $50 billion. This plan confirms GE’s intent to exit the banking business.

Immelt’s strategies have contributed to a build-up of cash. At the end of 2012, over $100 billion had been kept offshore to avoid a special federal repatriation tax. As such, GE is a member of a controversial group of American companies experiencing “trapped cash” thought to exceed $1.7 trillion across this group of corporations. In 2015, GE announced a repatriation program for part of its cash balances.

As Chairman and CEO of GE, Immelt has come under attack for leading GE towards legally avoiding paying US federal corporate taxes. GE’s tax positions have become a major item in Immelt’s agenda. GE’s local taxes in Connecticut have increased 5 times since 2011, and the state had approved yet another revised tax policy in early 2015. Immelt threatened to move GE”s headquarters out of Connecticut if the state would not back away from the tax plan.

In April 2015, Immelt won the 20th edition of the Leonardo International Prize “as a foreigner who reinforced his country’s cultural and economic ties with Italy.”

On 24 December 2015, Immelt was listed by UK-based company Richtopia at number 50 in the list of 500 Most Influential CEO’s.

GE could not escape the 2008 crisis that was fueled by the mortgage-backed securities debacle on Wall Street and the liquidity crisis that brought the derivatives market to its knees. GE’s major financial business, then known as GE Capital, was operated largely through the General Electric Credit Corporation subsidiary. As part of their response to the credit crisis, GE joined Goldman Sachs and Morgan Stanley in forming a wholly owned banking affiliate that qualified as a Savings and Loan Association. This entitled the subsidiary to FDIC insurance at the cost of regulation as a bank holding company. Aid received from the Federal Reserve by GE became a political issue in the 2016 presidential campaign.

In 2016, Immelt spoke at the commencement for Clemson University’s College of Arts, Architecture, and Humanities as well as the College of Engineering and Science. Clemson awarded Immelt with an honorary doctorate and Immelt spoke of how GE hired many Clemson alumni at their gas turbine factory in Greenville, South Carolina.

On June 12, 2017, GE announced that Immelt would retire as CEO and would be replaced by John L. Flannery. Immelt officially stepped down in October, 2017. In the interim, he was initially a top candidate to become CEO of Uber, replacing founder Travis Kalanick. He was initially Kalanick’s favorite for the post, in part because he was still open to Kalanick still having a significant role. However, Immelt’s presentation before the board was an unmitigated disaster. He didn’t seem to understand the nature of Uber’s business; one director called his presentation “a bad joke.” Even Kalanick realized that Immelt was not cut out for the job. When a board member privately told Immelt that he had no chance of winning the job, Immelt pulled out just before the board was to begin deliberations.

In 2017, Immelt was honored with an Edison Achievement Award for his commitment to innovation throughout his career.

On February 7, 2018, Immelt became the chairman of the board at athenahealth. Also in February, 2018, two weeks after the athenahealth announcement, Immelt joined the board of directors of Radiology Partners. On June 6, 2018, Immelt was named executive chairman of athenahealth. By November 2018, athenahealth entered into an agreement to be acquired by a private equity firm, in a cash-for-stock offer brokered by Immelt. Once the acquisition was completed, company was no longer publicly traded and Immelt stepped down.

Immelt was first announced as a board member and the Chairman of Tuya Smart’s Strategic Advisory Committee in September 2019. He was officially announced as the Chairman of Tuya Smart’s Global Strategic Committee at the company’s AIoT Business Conference on October 25, 2019 to help strengthen global strategic expansion of Tuya Smart’s IoT platform. Immelt attended the Consumer Electronics Show (CES) in 2020 on behalf of Tuya Smart.

On June 30, 2020, Immelt was announced as an advisor to Built Robotics. He joined Eric Sellman, Vice President of Civil at Mortenson, in the role.