you are right. IR has no numerical limit, but consumes 480,000 quota.
Read it through INA 201 highlighted in red -> blue -> purple.
I looked into immigration statistics of recent 3 years. Looks like there are HUGE number of GCs(~400k) issued to IR of US citizen annually.
I would say it probably makes quite a difference in cut-off date advancement if HR1645 gets passed.
INA 201(b) & 201(c)
(b) Aliens Not Subject to Direct Numerical Limitations. - Aliens described in this subsection, who are not subject to the worldwide levels or numerical limitations of subsection (a), are as follows:
(1) (A) Special immigrants described in subparagraph (A) or (B) of section 101(a)(27) .
(B) Aliens who are admitted under section 207 or whose status is adjusted under section 209 .
(C) Aliens whose status is adjusted to permanent residence under section 210 , or 245A .
(D) Aliens whose removal is canceled under section 240A(a) .
(E) Aliens provided permanent resident status under section 249 .
(2)(A)(i) Immediate relatives. - For purposes of this subsection, the term ``immediate relatives'' means the children, spouses, and parents of a citizen of the United States, except that, in the case of parents, such citizens shall be at least 21 years of age. In the case of an alien who was the spouse of a citizen of the United States for at least 2 years at the time of the citizen's death and was not legally separated from the citizen at the time of the citizen's death, the alien (and each child of the alien) shall be considered, for pur poses of this subsection, to remain an immediate relative after the date of the citizen's death but only if the spouse files a petition under section 204(a)(1)(A)(ii) within 2 years after such date and only until the date the spouse remarries. 3/ For purposes of this clause, an alien who has filed a petition under clause (iii) or (iv) of section 204(a)(1)(A) of this Act remains an immediate relative in the event that the United States citizen spouse or parent loses United States citizenship on account of the abuse.
(ii) Aliens admitted under section 211(a) on the basis of a prior issuance of a visa to their accompanying parent who is such an immediate relative.
(B) Aliens born to an alien lawfully admitted for permanent residence during a temporary visit abroad.
(c) Worldwide Level of Family-Sponsored Immigrants. -
(1) (A) The worldwide level of family-sponsored immigrants under this subsection for a fiscal year is, subject to subparagraph (B), equal to -
(i) 480,000, minus
(ii) the sum of the number computed under paragraph (2) and the number computed under paragraph (4), plus
(iii) the number (if any) computed under paragraph (3).
(B) (i) For each of fiscal years 1992, 1993, and 1994, 465,000 shall be substituted for 480,000 in subparagraph (A)(i).
(ii) In no case shall the number computed under subparagraph (A) be less than 226,000.
(2) The number computed under this paragraph for a fiscal year is the sum of the number of aliens described in subparagraphs (A) and (B) of subsection (b)(2) who were issued immigrant visas or who otherwise acquired the status of aliens lawfully admitted to the United States for permanent residence in the previous fiscal year.
(3) (A) The number computed under this paragraph for fiscal year 1992 is zero.
(B) The number computed under this paragraph for fiscal year 1993 is the difference (if any) between the worldwide level established under paragraph (1) for the previous fiscal year and the number of visas issued under section 203(a) during that fiscal year.
(C) The number computed under this paragraph for a subsequent fiscal year is the difference (if any) between the maximum number of visas which may be issued under section 203(b) (relating to employment-based immigrants) during the previous fiscal year and the number of visas issued under that section during that year.
(4) The number computed under this paragraph for a fiscal year (beginning with fiscal year 1999) is the number of aliens who were paroled into the United States under section 212(d)(5) in the second preceding fiscal year-
(A) who did not depart from the United States (without advance parole) within 365 days; and
(B) who (i) did not acquire the status of aliens lawfully admitted to the United States for permanent residence in the two preceding fiscal years, or (ii) acquired such status in such years under a provision of law (other than section 201(b)) which exempts such adjustment from the numerical limitation on the worldwide level of immigration under this section.
(5) If any alien described in paragraph (4) (other than an alien described in paragraph (4)(B)(ii)) is subsequently admitted as an alien lawfully admitted for permanent residence, such alien shall not again be considered for purposes of paragraph (1). 2/