Even though the IRS issues 9 out of 10 tax refunds within 21 days, it's possible your return may require additional review and take longer to process.
Also, the PATH Act requirements and other identity-protection safeguards implemented by the IRS may account for longer wait times.
Please look at the article below to see the list of things that can delay a refund.
Why do some refunds take longer than others?
If it's been processed and accepted, you can begin to track your refund at the IRS Where's My Refund? site.