I am receiving long-term disability payments from a private insurance company, and I was recently approved for CPP-D coverage for the same disability. The insurance company is now reducing my monthly payments to "offset" the payments from CPP-D. Are they allowed to reduce the payments by more than the gross amount that CPP-D is paying?

Typically, most LTD policies do allow the insurer to do this. You can, however, ask your LTD provider to show you where in the Policy it states they have the right. They can only do this if the policy says so.
If you have further questions on this topic, please reach out to our disability specialist, Rebecca, at rebecca.permis@stlawyers.ca, and she will help (at no charge).