Legislation that will establish a devolved Scottish social security system is to be passed by MSPs later.
Holyrood is being given responsibility for 11 benefits, including disability living allowance, personal independence payments and carer's allowance.
The benefits are relied upon by 1.4 million people across the country, and are worth about £3.3bn a year.
The devolution of the powers is being staggered, with the benefits system due to be fully operational by 2021.
The payments will be administered by a new Scottish social security agency, headquartered in Dundee and Glasgow, with 1,500 jobs split across the two sites.
A further 400 people will be employed at smaller sites across the country.
- Watch the debate and vote on the Social Security Bill through Holyrood Live from 14:10 with the vote at 19:10.
'Respect and dignity'
The Scottish government has described the changes as a "golden opportunity" to set up a system with "respect and dignity" at its heart.
And it has said the benefits agency would be "a new public service of which we can all be proud", and which would "deliver for the people of Scotland".
It estimates that 500,000 people or families are currently not claiming benefits they are entitled to, and is to spend £300,000 to encourage take-up.
The benefits which are being devolved from Westminster to Holyrood are:
- Personal Independence Payments
- Carer's Allowance
- Attendance Allowance
- Disability Living Allowance
- Winter Fuel Payments
- Cold Weather Payments
- Severe Disablement Allowance
- Industrial Injuries Disability Benefits
- Funeral Expenses Payments (to be replaced by Funeral Expense Assistance)
- Sure Start Maternity Grant (to be replaced by Best Start Grant)
- Discretionary Housing Payments
MSPs unanimously backed the principles of the Social Security (Scotland) Bill – which lays the foundations for the new system – in December, with the final debate and vote being held on Wednesday afternoon.
Speaking ahead of the debate, Social Security Minister Jeane Freeman said she had worked closely with the UK government's Department for Work and Pensions.
"Our plans are certainly on track," she said.
"I need to be sure that the DWP – who have to transfer information to us and work with us – that their plans match ours.
"But so far we have had really good working relationships with our colleagues south of the border, in government and in the DWP, and I am confident that we will work all this through."
Despite their overall support, opposition parties expressed some concerns about the bill at the time – with the Conservatives and Labour both calling for amendments to be made.
The Scottish government confirmed last week that the bill will be changed to remove a limit on how long a terminally-ill patient must have left to live before they are fast-tracked to the highest rate of disability benefits.
It had been under pressure to do so from opposition parties, medical professionals and charities.
Michelle Ballantyne MSP, who speaks for the Scottish Conservatives on this issue said she was concerned the Scottish government may not be ready to take over the 11 benefits.
"They've had years since they were told they would get welfare powers and they haven't done what we would have expected in terms of preparing for that," she said.
"The DWP and the UK government are saying they will give support, that they will try to prop up any issues that arise as a result of the Scottish government's lack of preparation."
Scottish Labour has suggested the Scottish government could be more ambitious with changes to benefits.
The party's social security spokesman Mark Griffin said: "We want them to top-up child benefit by £5 a week which would lift 30,000 kids out of poverty.
"We want them to split payments in households with Universal Credit so that women aren't susceptible to domestic abuse – if they live with an abusive partner, that they don't just take all the money that's coming into the household."
Audit Scotland has previously warned that the Scottish government had "not clearly estimated" the financial cost of putting the new welfare powers into practice.
The UK government is making a one-off payment of £200m to support the implementation of the new powers.
But Audit Scotland warned: "The Scottish government has not estimated the total cost of implementation, or the extent to which this will exceed the UK government's agreed contribution. The excess will require funding from the wider Scottish budget."