**NOTE*** Due to the Corona virus the IRS is operating short staffed. All field offices are closed and some processing centers are all but closed. Any tax return that requires hand processing will probably have long delays. Mailed returns are not being processed at all at this time. Most phone service has been curtailed.
https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue

Per DoninGA:

The IRS target is 21 days from the tax return being Accepted to issue a tax refund.  It is NOT a Guarantee

Did you e-file your tax return and was it accepted?
Only the IRS and your State control when and if a Federal or State tax refund is Approved and Issued.

You complete your tax return by finishing all 3 Steps in the File section. In Step 3, to e-file your tax return, you must click on the large Orange button labeled "Transmit my returns now".

After completing the File section and e-filing your tax return you will receive two emails from TurboTax. The first email when your tax return was transmitted and the second email when the tax return has either been accepted or rejected.

Note - 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.  Only the taxpayer listed on the tax return can obtain the status of a tax refund or a tax return.

To check the status of an e-filed return, open up your desktop product or log into your TurboTax Online Account. You can find your status within the TurboTax product.

If accepted by the IRS use the federal tax refund website to check the refund status - https://www.irs.gov/refunds

If accepted by the state use this TurboTax support FAQ to check the state tax refund status - https://ttlc.intuit.com/questions/1899433-how-do-i-track-my-state-refund

After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website.

See this IRS website for federal tax refund FAQ's - https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions

If over 21 days since being Accepted by the IRS and the tax refund is still Processing you can call the IRS and speak with an IRS agent concerning your tax refund.

Call the IRS: 1-800-829-1040 hours 7 AM - 7 PM local time Monday-Friday
When calling the IRS do NOT choose the first option re: "Refund", or it will send you to an automated phone line.
So after first choosing your language, then do NOT choose Option 1 (refund info). Choose option 2 for "personal income tax" instead.
Then press 1 for "form, tax history, or payment".
Then press 3 "for all other questions."
Then press 2 "for all other questions."
- When it asks you to enter your SSN or EIN to access your account information, don't enter anything.
- After it asks twice, you will get another menu.

Press 2 for personal or individual tax questions.
Then press 4 for all other inquiries
It should then transfer you to an agent.