A beneficiary can access funds from their RDSP by either annual payments (Lifetime Disability Assistance Payments) or occasional lump sum payments (Disability Assistance Payments). These payments can be used for any purpose. Income tax doesn’t apply to the original contributions, only to investment earnings, rollover amounts, grants and bonds.
There are a few rules that apply to RDSP withdrawals. Beneficiaries should plan to earn all their grants and bonds 10 years before they start drawing an income, because any grants or bonds received in the 10 years preceding withdrawals or payments must be repaid to the government. Lifetime Disability Assistance Payments can begin at any time, but have to start by the end of the calendar year in which the beneficiary turns 60.
To find out more about RDSP payments and rules, check the Government of Canada website