The IRS issues most refunds from e-filed returns in about 21 days, although some returns take more time to review.
https://ttlc.intuit.com/community/refund-status/help/when-will-i-get-my-irs-tax-refund/00/25589
Please see below for more information from the IRS regarding refunds and refund delays.
https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions
