The IRS normally pays tax refunds in about 3 weeks for e-filed returns and 6 weeks for mailed returns. If it will take longer, they sometimes send a letter. Amended returns can take up to 9 months.
What year are we talking about? How did you file (e-file or mail)? When did you file? Have you recently moved, and does the IRS have your current address if they need to mail a document to you?
You can also log into your IRS account and use Get Transcript to see if there is anything on file for that year.
https://www.irs.gov/individuals/get-transcript
It's possible if you e-filed, that it was rejected and you never submitted a corrected version. Or if you mailed your return, it could have gotten lost in the mail. Or there could be other issues.
