This news item expired on Wednesday, September 30, 2020 so the information below could be outdated or incorrect.
From HHS:
The Internal Revenue Service (IRS) has reopened registration for economic impact payments (EIP) to families who were unable to enter their information before the last deadline. Eligible families should fill out the EIP registration form by September 30 to receive $500 per child.
Those eligible to provide this information include people with qualifying children who receive Social Security retirement, survivor or disability benefits, Supplemental Security Income (SSI), Railroad Retirement benefits and Veterans Affairs Compensation and Pension (C&P) benefits and did not file a tax return in 2018 or 2019.
The IRS anticipates the catch-up payments, equal to $500 per eligible child, will be issued by mid-October. You will receive these payments the same way you received all other IRS payments, either by direct deposit or mailed check.
The IRS urges certain federal benefit recipients to use the IRS.gov Non-Filers tool through September 30 to enter information on their qualifying children to receive the supplemental $500 payments. If you are unable to enter your child’s information by September 30, you must wait until next year to claim your payment. Anyone who filed or plans to file either a 2018 or 2019 tax return should file the return and not use this tool.
For those unable to access the Non-Filers tool, they may submit a simplified paper return following the procedures described in this FAQ on IRS.gov.