Could be number of reasons for refund delays, especially this year. Generally it is due to dependent verification, refund offset, or information mismatch. You can get a free transcript of your return to review of any holds or codes. Click here to get your free online transcript.
Did you have unemployment benefits. So to not have to process thousands of amended returns, if you had unemployment benefits the IRS could be holding your return for processing once their systems are updated for the American Rescue Plan Act that excludes the first $10,200 of unemployment benefits if your adjusted gross income is less than $150,000.
If you have earned income credit and/or additional child tax credit, it is probably delayed. Returns with either of these credits are covered under the PATH act, which gives the IRS authority to delay the refund to verify dependent information on your return. For 2020, the IRS was not issuing refunds for these returns until the 1st week of March.
Do you have any refund offsets such as back taxes, student loans, child support, state obligations (Court costs), etc. This could delay your refund and you will receive a letter indicating the change.
If you answered the stimulus questions incorrectly, this will delay your refund. If you claimed the Recovery Rebate credit on your return, the IRS is matching stimulus payments to returns with the Recovery Rebate credit. If there is a mismatch, you will be receiving a letter.
Keep checking IRS.gov "Where's my Refund" for the most up to date information.
Check here also for more information on refund delays.