See IRS 1040 Instructions.
https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
For line 4 page 26 top of last column……
Except as provided next, leave line 4a blank and enter the total distribution (from Form 1099-R, box 1) on line 4b.
For line 5 page 27 bottom of last column……
If your pension or annuity is fully taxable, enter the total pension or annuity payments (from Form(s) 1099-R, box 1) on line 5b; don’t make an entry on line 5a.
