Does the government reclaim RDSP grants and bonds when the beneficiary dies in Ontario?

Often, at least in part. RDSPs receive federal government contributions, grants and bonds, on top of personal savings, and when the plan has to be closed because the beneficiary has died, the program generally requires some of the more recently received grant and bond money to be repaid to the government rather than paid out with the rest of the plan. Contributions and grants that have been in the plan longer are generally treated differently from ones received more recently, but the specific repayment formula and timeframes are set by the federal program and can change, so it's not something to estimate on your own.

Because this is a federal program rule, not an Ontario estate law issue, the estate trustee handling the RDSP after death should go directly to the RDSP issuer for the exact repayment calculation that applies to that specific plan, rather than relying on general assumptions from articles or past experience with a different plan.

Getting an accurate number early helps the estate trustee know what's actually available to distribute, since assuming the full account balance is available could create problems later in the estate administration.