第一轮($1,200) 简单粗暴： 只要联合报税一方是ITIN，即使另一方有SSN也不能领，而且儿童也不能领。也就是说“一人ITIN，全家不能领”
When you file a tax return with a spouse that isn’t a citizen, that spouse doesn’t have a Social Security Number to put down. Instead, you typically enter an Individual Taxpayer Identification Number, or ITIN. If you used an ITIN, then anyone on that tax return was ineligible for a stimulus check – including your children. A family of five where both parents are citizens and they earn less than $150,000? They would receive the full $3,900. A family of five where one parent is a non-citizen and they earn less than $150,000? They would receive nothing.
来源：Forbes
更新：以下只是媒体的报道，还未得到条款原文的官方确认。
更新2：原文出来了（长达5500多页。。。），确认了以下内容。
(4) VALID IDENTIFICATION NUMBER.—
(A) IN GENERAL.—For purposes of this subsection, the term ‘valid identification number’ means a social security number (as such 2 term is defined in section 24(h)(7)).
(2) JOINT RETURNS.—In the case of a joint return, the $1,200 amount in subsection (a)(1) shall be treated as being—
(A) $600 if the valid identification number of only 1 spouse is included on the return of tax for the taxable year, and
(B) zero if the valid identification number of neither spouse is so included.
(3) QUALIFYING CHILD.—A qualifying child of a taxpayer shall not be taken into account under
subsection (a)(2) unless—
(A) the taxpayer includes the valid identification number of such taxpayer (or, in the case of a joint return, the valid identification number of at least 1 spouse) on the return of tax for the taxable year, and
(B) the valid identification number of such qualifying child is included on the return of tax for the taxable year.
来源：https://rules.house.gov/sites/democrats.rules.house.gov/files/BILLS-116HR133SA-RCP-116-68.pdf
也就是说，这一轮+ 修正上一轮：在收入和其他情况符合要求前提下，有SSN的成人和儿童两轮都可以领，而持ITIN的不行。
符合第二轮条件（有SSN）、但第一轮因为家庭成员ITIN原因没有领到钱的，似乎将会追加第一轮的款，因为第一轮的细则已经修正到跟这一轮一致（见 p.1999-2001)。