Does the IRS have access to the USCIS immigration data for former lawful permanent residents (LPRs)?
Information about former LPRs, such as the individuals names, is not published under the statute, IRC Section 6039G, which only covers former U.S. citizens. 
This raises the question of whether the Department of Homeland Security tracks former LPRs – names and addresses overseas and provides that information to the Internal Revenue Service?
A prior post discussed the newly published USCIS immigration form I-407 for LPRs who must now use it when formally abandoning LPR status. See, More Information and More Information: USCIS Creates New Form for Abandonment of Lawful Permanent Residency
The new I-407 Form requires much more information and is 2 pages in length. The old form had only 6 lines and was less than 1/2 of a page in length. These forms 
are set forth here. The new form requires the address overseas of the individual.
As readers here know, the names of former U.S. citizens are published quarterly by the U.S. federal government for the world to see. See a prior post, The 2014 Third Quarter Renunciations Is probably the New Norm –
The complete set of lists going back to the mid-1990s can be reviewed here. Quarterly Publications.
Of course, the IRS can easily select and identify individuals for audit, by simply drawing from the published names of former U.S. citizens, which is currently tracking at an average of about 850 former USCs quarterly. In contrast, the number of former LPRs who have filed USCIS Form I-407 is tracking at an average of about 4,000 to 5,000 individuals quarterly. 
While citizens are often the focus of the public press and Congress regarding “expatriation taxation”; the statute also wraps in so-called “long-term residents.” These are individuals who had or continue to have “lawful permanent residency status.” There are numerous technical considerations in this area, but needless to say, the number of former lawful permanent residents who have simply filed Form I-407 – Abandonment is far in excess of those U.S. citizens who have filed for and received a Certificate of Loss of Nationality (“CLN”) – Form DS-4083 (CLN). The graph reflects the enormous difference.
See, earlier post The Number of LPRs “Leaving” the U.S. is 16X Greater than the Number of U.S. Citizens Renouncing Citizenship
On a related post, the question was raised –What are the Number of LPRs who Leave U.S. Annually without filing Form I-407 – Abandonment?
This is important, since many LPR individuals will have “expatriated” without actually having filed USCIS Form I-407. See, Oops…Did I “Expatriate” and Never Know It: Lawful Permanent Residents Beware! International Tax Journal, CCH Wolters Kluwer, Jan.-Feb. 2014, Vol. 40 Issue 1, p9 
While the IRS has specific information about U.S. citizens, it is not clear whether the Department of Homeland Security via the USCIS provides data to the IRS regarding lawful permanent residents who have filed Form I-407? If such an individual becomes a “covered expatriate” under the U.S. tax law, the range of adverse tax consequences can follow them and their future beneficiaries and heirs, including as follows:
- “mark to market” taxation on their worldwide assets,
- 40% inheritance tax to U.S. beneficiaries,
- 40% tax on gifts to U.S. beneficiaries,
- etc.
It seems fairly easy, from a legal perspective, that the IRS can request the names, addresses (and indeed the newly completed form) from the USCIS of all individuals who have filed USCIS Form I-407. From the USCIS records, the IRS will be able to determine if the individual was a “long term resident” based upon the number of years the individual had such status.
Assuming the IRS determines the individual is a long term resident, they can then simply check to see if the they have received IRS Form 8854 from the former LPR; in order to determine if she or he satisfied the certification requirement of Section 877(a)(2)(C). If not, the IRS will necessarily know the individual is a “covered expatriate.”