Effective for tax years beginning after July 1, 2019, the Taxpayer First Act, Pub. L. No. 116-25 Section 2301, requires organizations exempt from taxation under section 501(a) to file their annual Form 990 and Form 990-PF returns electronically, unless covered by one of the exceptions listed in the form instructions.  Form 990-EZ filers are required to file electronically for tax years ending July 31, 2021, and later. This IRS News Release contains a summary of e-filing requirements.

From Annual Filing and Forms | Internal Revenue Service (irs.gov)