The national travel concession scheme which offers Scotland-wide travel to the over 60s on local, registered or scheduled long-distance services is coming under increasing financial scrutiny as life expectancy increases and people stay in employment longer.
Last year the Scottish Government draft budget on concessionary travel revealed that the £207.8 million budget for 2016-17 was to be cut by £9.5m for the year 2017-18.
Mr Yousaf will face questions on the issue in the Scottish Parliament today.
However, Mr Yousaf, announcing the consultation, stressed that existing holders would retain their bus passes.
He also said he want to extend the scheme to Modern Apprentices and groups of people who were in “the most need”.
Mr Yousaf said: “If you’ve got a free bus pass you will continue to have that free bus pass and continue to be able to use that pass in the way that you currently are.
“What we have said is that we want to extend the national travel scheme to Modern Apprentices, to those on a Job Grant, so that some young people, that are in the most need, can also benefit.
“But clearly people are living longer, they are staying in work longer – which are all good things – but it does add a pressure.
“So we will consult on the long-term sustainability of the national concession travel scheme and we look forward to hearing people’s views.”
Mr Yousaf refused to clarify if the age for getting free travel would rise.
“I don’t want to pre-empt any consultation,” he added.
“We are getting continued cuts from the Westminster government and we have to make sure our budgets go further.
“So if you have a pass you will absolutely continue to have that pass. I would urge everyone to get involved in the consultation.”
Neil Bibby, MSP, the Scottish Labour transport spokesman, said: “The free bus pass provides a life-line to many older people and they deserve to know what proposed changes the SNP are coming up with ahead of the council elections in May.”
Will Searle, Age Scotland spokesman, said: “The concessionary travel scheme is vital for Scotland’s older people, helping tackle loneliness and isolation.
“Older people must be fully consulted on how it will be provided in the future.
“We are keen to play our role in this discussion, but that must include issues such as better support for community transport and protecting bus routes which are lifelines for older people in our communities.”