I'm past the income section but haven't been able to enter my 1099-R?

[SweetieJean]

Click on Wages and Income > Retirement.

[VolvoGirl]

You can go back.  You can jump around.  Click on 

Federal Taxes on the left side

Wages & Income at the top

Then scroll way down to Retirement Plans and Social Security,

Then IRA, 401(k), Pension Plans (1099R) - click Start or Revisit

If you are filing a Joint return be sure to pick which person it is for.