But it warned a “huge amount” of work remains, including around timescales and staffing levels.
New benefits introduced in Scotland include the Scottish Child Payment, Child Disability Payment and Adult Disability Payment.
The Scottish Government has committed more than £3.9 billion for benefit expenditure in 2022/23, which is set to provide support to more than one million people.
Audit Scotland said while people are positive about their experiences of Social Security Scotland, the scale of activity undertaken by the department will increase over the next few years – with the direct administration of devolved benefits jumping from around 20 per cent to more than 70 per cent by 2025.
The number of benefits cases administered by Social Security Scotland is expected to rise – an example being the Adult Disability Payment, which is projected to increase from 20,000 in 2022 to 475,000 by 2026/27.
The department also requires a doubling of its current workforce within the next year to deal with growing administration needs.
However, the report suggests the Scottish Government is “well placed” for the next stages of implementation, calling the delivery to-date a “significant achievement”.
Social security minister Ben Macpherson said: “I am pleased that this Audit Scotland report recognises the significant progress we have made in building a new public service from scratch since 2018 and delivering 12 benefits – seven of which are completely new forms of financial support that are not available anywhere else in the UK.”
He added: “I am proud that we have built our social security system with the people who will use it, and appreciate that the report acknowledges our focus has delivered a service built on our principles of dignity, fairness and respect.
“The report also notes the positive feedback people have shared about their experiences of engaging with Social Security Scotland.
“We have been ambitious in our delivery timeline, including introducing new benefits while dealing with the pandemic, and we are ensuring that we transfer tens of thousands of cases safely and securely from the DWP to Social Security Scotland.
“As well as delivering benefits now and in the period ahead, we are responsibly and ambitiously developing a new social security system that will serve Scotland for many years to come, putting people at the heart of everything we do.”
Caron Lindsay, social security spokeswoman for the Scottish Liberal Democrats, said: “It’s now almost eight years since the Smith Commission recommended the devolution of welfare powers to Scotland and it will still not be complete until 2025.
“These powers represent a major opportunity for Scotland to do things differently, but because of the time taken by the Scottish Government, disability benefits are rising at a lower rate and many powers remain in the hands of the DWP.”
Stephen Boyle, Auditor General for Scotland, said: "Successfully launching new benefits during the pandemic has been a significant achievement for the Scottish Government, but a huge amount of work remains.”