My federal tax return was less than what TurboTax said it would be, who can explain this to me, and also verify that IRS was correct?

[mesquitebean]

About how much less?   Did you choose to pay any TurboTax fees out of the Federal refund?  If so, that also has an additional 39.99 service fee (44.99 for California filers.)

Also, be sure you are considering only the Federal refund amount, shown on Line 20a of  your Form 1040.   If you are also getting a state refund, it comes separately.  So do not use a "total refund" amount.

If the IRS reduced your refund, they should send you a letter in about 3 weeks or so explaining why.   There may also be some info at "Where's My Refund" about a change in your refund amount:
<a rel="nofollow" target="_blank" href="https://www.irs.gov/Refunds">https://www.irs.gov/Refunds</a>

No product is shown by your screen name above.  What product edition did you use, and was it Online or desktop software?  Did you prepare both Federal and State returns?    Did you purchase the Live feature for access to a CPA/EA tax expert?

[Doug9]

My federal tax return was less by $3000.00, I did receive a letter from IRS but it didn't help me figure out why there was a $3000.00 difference. My state return was exactly what TurboTax said it would be.  TurboTax Premier is the version I purchased.

[SweetieJean]

Call the number on the IRS letter and ask for an explanation.
Exactly $3,000?  Could you have made a data entry error using the number keypad on your PC?

[mesquitebean]

Is there a phone number on your IRS letter, so you can ask them for more info?  That would be the best place to start.

Did you purchase the Live feature for access to a CPA/EA tax expert?  If so, we can tell you how to use the Live feature.

You can also discuss IRS letters with the TurboTax free Audit Support Center.  To get the phone number, you can click on the blue "Get Help" button at this page and follow the prompts.
https://support.turbotax.intuit.com/irs-notice/audit-support/

Or here's how to reach regular TurboTax Support.   Hours Mon-Fri 5AM-5PM Pacific (8AM-8 PM Eastern.)

FAQ:  What is the TurboTax phone number?
https://ttlc.intuit.com/questions/1899263