Are there any rules against this?
Answers
A disability allowance may be seen as a passive source of income. It is advisable to seek advice to your specific case.
Foreigners from non-EU countries are eligible for the D7 visa. The mandatory requirement for applicants is to earn a passive income of at least €760 per month in another country and purchase or rent housing in Portugal. There are no specific rules against US disability benefits.
There are no problems related to the origin of your passive income in this case, as long as you have a regular monthly passive income of at least EUR 760.
The D7 Visa can be applied with a stable and continuous source of passive income and your US Government disability benefit would be considered as such.
Government pensions are eligible for purposes of passive income proof for D7 application.