Eyolfson was acclaimed as the Liberal Party's nominee in Charleswood—St. James—Assiniboia—Headingley on March 30, 2015, and took a leave of absence from his medical practice during the campaign. Eyolfson won the election, unseating
Conservative incumbent and former cabinet minister
Steven Fletcher by over 6,000 votes in a huge upset. Eyolfson introduced his first private member's bill, C-373, an act respecting a federal framework on distracted driving in October 2017. Eyolfson's private member's bill would have the federal justice and transport ministers work with the provinces to create a framework aimed at deterring and preventing distracted driving. Eyolfson stated the reason he introduced the bill was due to his experiences as an emergency department physician where he treated multiple victims of distracted driving. The bill was defeated at Second Reading March 21, 2018. In October 2017, Eyolfson sponsored S-228, the Child Health Protection Act in the House of Commons. The bill seeks to amend the Food and Drugs Act in an effort to fight childhood obesity by prohibiting the marketing of unhealthy food and beverages towards children. Eyolfson stated his previous experience as a doctor and his desire to take steps towards reducing childhood obesity and the risk of premature onset of chronic conditions such as Type 2 diabetes and heart disease as his reasoning for sponsoring the legislation. On April 18, 2018, the Standing Committee on Health tabled its report Pharmacare now: prescription medicine coverage for all Canadians. Eyolfson, a member of the health committee, helped draft the committee's report. The committee made 18 recommendations it said could form a blueprint for a new single-payer, publicly funded prescription drug program for all Canadians. Eyolfson told the Winnipeg Free Press that a national pharmacare program would mean "the ability to bulk-buy [pharmaceuticals] would save billions of dollars a year," and could introduce provinces to newer, cheaper medications that are more effective. In his community report, Eyolfson stated, "It's evident a National Pharmacare Plan would both save billions annually and save lives. As a result, I’m calling upon the government to fully implement a National Pharmacare Plan that is universal, comprehensive, evidence-based, and sustainable." Due to the rising number of incidents related methamphetamine abuse in Manitoba, Eyolfson tabled a motion for the Standing Committee on Health to study the impacts of methamphetamine abuse in Canada in order to develop recommendations on actions that the federal government can take, in partnership with the provinces and territories. The committee unanimously agreed to his study. Regarding the outline of the committee study, Eyolfson said, "the medical evidence says that if you’re dealing with drug problems, the number of things that need to be factored in go so far beyond the actual substance; you look at the root causes,” In a community report prepared by Eyolfson, he wrote that sixty one per cent of nurses report abuse, harassment or assault on the job over a one-year period which leads many to suffer from the effects of PTSD. And that from 2006 to 2015, there were nearly 17,000 violence-related lost-time claims for health care workers. In 2016, this cost Canada nearly a billion dollars as a result of absenteeism for full-time nurses due to illness or injury. In a statement in the House of Commons, Eyolfson said, “As an emergency room physician for 20 years, I would regularly be exposed to violence, even on two occasions having been assaulted myself… It is evident that there is a need for federal engagement on this issue, which is why I introduced a motion in the health committee to study and develop recommendations on actions that the federal government could take to improve violence prevention in health care.” On March 1, 2019, Eyolfson tabled a petition in the House of Commons to address violence against health care workers. The petition had 8,743 signatures from every province and territory in Canada. His petition called upon the Minister of Health to develop a pan-Canadian prevention strategy to address growing incidents of violence against health-care workers. Eyolfson hopes that a national prevention strategy would continue to change perceptions that violence in workplace settings was acceptable. Eyolfson stated, "Part of it's a cultural shift. It was always just simply accepted that this was a 'part of the job…It took a long time for society, in general, to say that, 'No, this is not acceptable in the hospital workplace; this is not acceptable in any workplace.’" Because of his experience in emergency medicine, Eyolfson was brought in to support the task force from a public health perspective. Eyolfson ran for re-election in Charleswood—St. James—Assiniboia—Headingley in the 2019 federal election. Amid a nationwide drop in Liberal support from the 2015 election, he lost to Conservative challenger
Marty Morantz by a margin of 2,417 votes. He challenged Morantz in
2021. After the first count of the ballots on polling day, September 20, in the latter election, Morantz led Eyolfson by 24 votes, which touched off a mandatory recount. Eight days later, Eyolfson conceded after the validated results had widened Morantz's lead to 460 votes, which was approximately 1 per cent of the total vote. Eyolfson ran in
Winnipeg West in the
2025 Canadian federal election and defeated Conservative incumbent Marty Morantz by a margin of 7,606 votes ==Personal life==