He stated the Bill would "deliver vital savings to ensure legal aid can be targeted at those who need it most".
The cost of providing legal aid amounted to £157.3 million last year, the second highest total on record, but the Scottish Government hopes the Scottish Civil Justice Council and Criminal Legal Assistance Bill will cut that by almost £4 million.
Mr MacAskill said: "Contributions to criminal legal aid will allow us to continue to target legal aid at those who need it most by asking those who can afford it to pay towards the cost of their defence."
He continued: "To be clear, no one is being asked to pay for the full cost of their defence. If they can do that, they would not be eligible for legal assistance.
"We are suggesting that where someone can afford to contribute towards the costs, they should be asked to do so."