The final rule will apply only to applications and petitions postmarked (or if applicable, submitted electronically) on or after Feb. 24, 2020. For applications and petitions sent by commercial courier (such as UPS, FedEx, and DHL), the postmark date is the date reflected on the courier receipt.
When determining whether an alien is likely to become a public charge at any time in the future, DHS will NOT consider an alien’s application for, certification or approval to receive, or receipt of certain non-cash public benefits BEFORE Feb. 24, 2020. Similarly, when determining whether the public benefits condition applies to applications or petitions for extension of stay or change of status, USCIS will only consider public benefits received on or after Feb. 24, 2020.
USCIS will post updated forms and submission instructions to the USCIS website during the week of Feb. 3 to give applicants, petitioners, and others time to review updated procedures and adjust filing methods. After Feb. 24, except in Illinois, USCIS will reject prior editions of forms if the form is postmarked on or after Feb. 24, 2020. If USCIS receives an application or petition for benefits using an incorrect edition of the forms, the petitioner or alien will need to submit a new application or petition.
DHS remains enjoined from implementing the final rule in Illinois. If the injunction in Illinois is lifted, USCIS will provide additional public guidance.
https://www.uscis.gov/i-864
Public Charge Toolkit.