1. I am not sure but it is HEPATITIS B done montly.
2. If the applicant is unable to make this payment, another person can make this payment on the applicant’s behalf.
Failure to Pay
The applicant will not receive a green card until the required USCIS Immigrant fee is paid.
Failure to pay does not affect the lawful status of the applicant. While the applicant can use their Customs and Border Protection (CBP) Form I-94, Arrival and Departure Record, for one year to document they are a lawful permanent resident, once that I-94 stamp expires, the applicant will need to possess a green card as evidence of their lawful permanent resident status.
Anyone can correct me if am WRONG coz am not an EXPERT