You could request a free wage and income transcript from the IRS to see what income was reported to the IRS by your employers and/or financial institutions.  Then compare that to the income you entered on the tax return.

https://www.irs.gov/individuals/get-transcript

 IRS Agent told me on the phone today, my late husbands Pension was NOT included!

I DID upload it, it is showing on the TurboTax  papers I've printed out.

HOWEVER,..how do I know if it was really submitted?? things happen, but that is not an answer

for IRS.

Check your 1040 line 5.  You may have got the wrong taxable amount on line 5b  OR the pension ended up on line 4 as a IRA and the IRS missed it,  

Mike, thank you! You had me look at something which had bothered me.

Line 5a is blank, Line 5b has both, my Pension AND my late husband's Pension!! For some reason, it was

combined. Now what do I do? When I spoke with the IRS Agent, she looked at THEIR papers and said

true, it is NOT included. So now I need to respond, say I agree and it will be worked on. That also means

that I would have to pay this amount of $4,475.00 which they added to the total.

I am overwhelmed and that is an understatement.

Mike, since you seem to be very informed, do you have any advice or suggestion please? 

Volvo Girl, thank you, very smart! what you said, is exactly what it is!

 YOU and MIKE, have helped a lot! Now, what do I do??? I Understand that People feel they might be held accountable for answers.

That is NOT the case with me. I've learned a lot here with the answers I've gotten. You, People, are just 

super!!! Still feeling super stressed, however, the answers I've had are very good.

NOW,  have to decide what to do next. Not as smart as you all are, so will have to write back to IRS and hope

they will review everything, so I do not have to pay double the taxes and or even penalties and Interest. 

Maybe he had another 1099R you didn't include or get?

thank you for trying. however, having spoken to both..Turbo Tax Person, and IRS person, do not believe

I will get any help! on Turbo Tax, I listed.....Soc Sec,..My Pension,..my late husband's Pension..

every year since 2016. No problems. 

This year, line 5a and line 5b was different, however, the total was the same as before.

So, whose fault is it? IRS simple says husbands pension is NOT listed!

Volvo Girl, thank you for trying. I,m giving up. since I have spoken to both parties, what else can I do.

will write to IRS, accept and hope they will re-check all. Guess that's life, not always fair. 

the bottom line is to compare IRS 
"record of account"

with your printout of your TurboTax original filing.

look for 
TOTAL PENSIONS AND ANNUITIES

TAXABLE INCOME

@terikas 

fanfare, cannot find *record of acct.* on the IRS papers.

embarrassed to say, I know nothing about taxes, or what Turbo tax papers to IRS look like.

However, because of all the answers I got from HERE, I've learned a lot. What to look for,

where to find it. What I do know now, I knew I had uploaded everything to Turbo tax. 

Now I also know that they listed everything unless I'm clueless and miss something.

They combined 2 pensions and subtracted the Non-taxable amount from Soc. Sec.  That is what I found.

2 pensions= mine and my late husband's pension. what could be wrong with that?

Had intended to call IRS again today since I cannot say *Yes I agree with you and I will pay*

Just sitting by the phone ready to dial, I'm shaking terribly. Wishing I had Man's voice and steady.

thank you fanfare, and all the rest of the people who answered, trying to help me, that I never expected. 

Under Get Transcript select "Income Tax" as your reason.

Record of Account is one of the several reports available to you.

Otherwise ,you might ask the IRS phone rep to pull that up and tell you the amounts  and/or mail it to you

There's no reason to be afraid of the IRS rep.

They can't take your money over the phone.

@terikas