Once a tax return has been Accepted by the IRS or a State, TurboTax receives no further information concerning the tax return or the status of any tax refund.
The IRS will be sending you a letter in the next few weeks explaining what they changed on your tax that caused your tax refund to be reduced.
No one knows why. The IRS does not share any information with TurboTax after you file your tax return. But there are a number of possibilities.
First----did you choose to pay your TurboTax fees from your federal refund? Your fees plus the extra "refund processing fee" of $39.99 (or $44.99 in CA) would have been subtracted from the refund before you received it.
When you choose "refund processing" TurboTax gets its fees when the IRS releases your refund. Your refund goes to the third party bank. The bank takes out your fees and then that bank sends the rest of the refund to you.
How can I see my TurboTax fees?
https://ttlc.intuit.com/questions/2565973-how-do-i-review-my-fees-in-turbotax-online
What is Refund Processing Service?
Santa Barbara Tax Products Group, LLC (SBTPG) is the bank that handles the Refund Processing Service when you choose to have your TurboTax fees deducted from your refund. This option also has an additional charge from the bank that processes the transaction.
You can contact them SBTPG, toll-free, at 1-877-908-7228 or go to their secure website www.sbtpg.com
https://ttlc.intuit.com/questions/2580357-who-provides-the-refund-processing-service
Or----did you owe any child support, back taxes, etc. that the IRS took to offset the refund?
Or.....did you add federal and state refunds together and only receive federal so far? They do not arrive at the same time. Federal and state refunds are processed separately and you get them at different times.
If the IRS reduced your federal refund, they will be sending you a letter in several weeks to explain why.