I mailed my paper 2019 return 9/10/21. I am still not able to track it on the IRS site. How long should I wait before trying to call the IRS?

You just mailed it in September?  It will take a long time to process, like over 6 months!   It won't show up on the irs refund lookup.  People who filed in February are still waiting.  

Good to know, thank you! I was getting nervous since the site says 6 weeks and I couldn't track it yet. I know, my fault for filing so late!

Follow the progress  thru your account at IRS.gov  :  https://www.irs.gov/payments/view-your-tax-account

@Critter-3  Thank you!

@VolvoGirl Good to know, thank you! I was getting nervous since the site says 6 weeks and I couldn't track it yet. I know, my fault for filing so late!