You can see what information is needed for CPP and OAS by looking at the tax slips for each. You can see them on these Canada Revenue Agency (CRA) webpages:
T4A(P) Statement of Canada Pension Plan Benefits
T4A(OAS), Statement of Old Age Security
However, we would highly recommend that you get the actual slips themselves, in order to be certain, you are entering the correct information.
To get a copy of your slips, visit Service Canada or call them at 1-800-277-9914.
You can also view them by logging into the Canada Revenue Agency (CRA)’s My Account service.
Or have TurboTax get the information from your My Account by using Auto-Fill. This TurboTax FAQ has instructions on how to use Auto-Fill in TurboTax Online: In TurboTax Online, how do I use Auto-fill my return?
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