Streamlined Foreign Offshore procedure
The US government has recognized that there are many Americans living abroad who do not know or did not know about their reporting obligations. To this end, they have created the Streamlined Foreign Offshore (SFO) procedure. This arrangement will eventually come to an end, but no end date has been set as of now.
The SFO procedure consists of 3 parts: 3 years of tax declaration of all worldwide income; 6 years of FBAR; and a personal statement explaining that you did not deliberately fail to file your returns. The tax declaration consists of a Form 1040 with various attachments (the tax return). This includes worldwide income, so not only your US income. The FBAR is a report of all your non-US bank accounts. The statement is a non-willful statement where you declare that you did not purposely intend to not file your returns, FBARs, or Form 14653.
To be able to follow an SFO procedure, a Social Security Number is required. Without a SSN, the procedure cannot be followed.
The returns and the non-willful statement must be sent to the IRS. The FBARs must be submitted separately to FINCEN.