People on incapacity benefit in NI face a re-assessment process which begins this week.
The government said the aim is to help those who are capable to get work. Some claimants may see their income cut.
76,000 people in NI will now face questionnaires and interviews conducted by an independent company.
The process is designed to assess if the claimant is fit for some type of work.
If so, they will be moved onto Job Seekers Allowance, meaning around a 30% cut in income for some .
People with limited capability for work will receive Employment and Support Allowance.
Those who are most disabled will not be expected to look for a job and will get a higher rate of employment allowance.
It will take three years for all the assessments to be completed and claimants will remain on the current level of benefits until they are called.
The Department for Social Development said claimants would be guided through the new process.
Around a quarter of claimants are likely to find themselves receiving less money.
The thinking behind the new system is that work increases confidence, health and self esteem.