Turbo Tax asks: "Tell us how much of your pension the plan administrator paid directly for health Insurance". Is that the monthly deduction from my check? or Box 5 1099R?

Yes, it most likely is the deduction from your monthly check, and also the annual total reflected in Box 5 on your 1099-R.

If you made any after-tax contributions to your pension, that could also be in Box 5.

The best way to tell is to look at your monthly payment statement from the Payor to verify any deductions from your pension.

Here's more info:

https://ttlc.intuit.com/replies/6052375