Adults who test positive for Covid-19 are advised they can now leave self-isolation after five days, even though they "might still be infectious".
Updated Department of Health guidance states that testing to leave isolation is "no longer advised".
Children can leave after three days as they "tend to be less infectious".
The Department of Health said the updated advice sought to strike the right balance between reducing transmission and mitigating disruption.
Previous guidance advised that those who tested positive following a Lateral Flow Test (LFT) should self-isolate for up to 10 days, either from the date of the test or when symptoms started, whichever was sooner.
However, this period could have ended earlier if the person had two negative LFT results taken 24 hours apart, with the first taken no earlier than day five.
On Friday, Northern Ireland's associate deputy chief medical officer Dr Joanne McClean advised people to "still be careful".
"We're no longer asking you to take a test before you leave your isolation but we are still advising you to be careful in those days between day five and day 10, where you might still be infectious," Dr McClean told BBC Radio Ulster's Evening Extra programme.
"It's really about trying to strike a balance between controlling transmission of the virus and the impact it's having on people's lives and society in general."
Despite the reduction in the self-isolation period, people are advised to avoid contact with individuals who are at a higher risk from Covid-19 for the full 10 days.
They are also advised to avoid visiting care homes, hospitals and other health and social care settings.
The new guidance comes as latest figures from the Office for National Statistics (ONS) show 1 in 25 people in Northern Ireland tested positive for the virus last week, with Covid infections rising again more generally across the UK.
A month ago, the Northern Ireland figure was 1 in 75.
Dr McClean said that while numbers had been going up in Northern Ireland, "early signs from other data we have about testing and hospitalisations, and importantly data we have from waste water testing, we think we are at, or are very near the peak of this wave".
"We hope that we will start to turn a corner soon," she added.
Dr McClean also said that the number of people in hospital with Covid was much lower than in previous waves.
'Use personal judgement'
The Department of Health also announced that lateral flow tests for Covid-19 would continue to be made available in Northern Ireland until the end of July.
The tests are currently available for those with coronavirus symptoms.
Health and social care staff, those visiting health and care settings and those providing care to someone at high risk if they contract the virus can receive the tests without having symptoms.
Health Minister Robin Swann said: "As we move forward together, and continue learning to live life Covid-aware, I would urge people to use personal judgment, to act responsibly and to take sensible actions to help stop the spread of Covid-19 and other respiratory infections.
"This in turn will help to protect those who are most vulnerable."