Check status of federal amended return
Use website: https://www.irs.gov/filing/wheres-my-amended-return
Please note that amended returns take up to 16 weeks to process under normal circumstances. Since Covid-19, processing times have been known to take significantly longer, particularly when amended returns are paper filed.
In the past, most amended returns required paper filing, but the IRS has recently modernized their practices. Now, many amended returns can be electronically filed.