My tax return is pending in my bank account for much less then my federal refund is supposed to be. I haven't received emails about why it would be less. What should I do

Please see this TurboTax FAQ on why your direct-deposit refund may be lower than what you expected: https://ttlc.intuit.com/community/refunds/help/why-is-my-direct-deposited-refund-or-check-lower-than-the-amount-in-turbotax/00/25594.The IRS will send you a letter of explanation when your refund is less than you expected you can also get this information by looking up your refund at the IRS Where's My Refund page.

If this is for a state refund please contact your state Department of Revenue, they will also send you a letter.

I also haven't received any letters. Is it possible for them to send it out in increments instead of all at once?

If you were expecting both Federal and state refunds, make sure which one your bank is expecting.  They come separately.    It could be a state refund, which can come first at times.

Or did the IRS "Where's My Refund" tool also say your funds had been sent?   If so, there may be additional info at the WMR tool, such as if there is an offset.  So check there, too.

https://www.irs.gov/Refunds

If the IRS reduced your refund, you should get a letter from them in about 3 or so weeks explaining why.  If you don't want to wait on the letter, then you'd need to phone the IRS and see if they can tell you what the reason is.

Here's how to reach a live agent at the IRS:

800-829-1040 (7AM-7 PM local time) Monday-Friday

When calling the IRS do not choose the first choice re: "Refund", or it will send you to an automated phone line.

• First choose your language.  Then listen to each menu before making the selection.
• Then press 2 for "personal income tax".
• Then press 1 for "form, tax history, or payment".  
• Then press 3 "for all other questions."
• Then press 2 "for all other questions." 
• It may then ask for your SSN, but do not enter it.  Just wait.    If it asks for SSN a second time, still do not enter it.
• Then it will get "tired", and you'll get another menu.  Choose 2 for "personal" then you should be transferred to an agent, but there's likely to be a long wait.
• I usually use a speakerphone so I can work on something else while waiting.