As far as I can glean from the various news articles of recent days and from older country reports from the likes of PWC and KPMG about how the tax has worked in the past, the Bienes Personales tax has always applied at 31 December to all “residents for tax purposes” (that would be all Argentines and—with one exception detailed below—any expat on any temporary or permanent visa once he or she has completed the first 12 months of their temporary residency) who have worldwide assets greater than the quite low minimum threshold. The change now, again as far as I can glean, is two-fold: (i) a massive increase to the amount of the tax; (ii) closing the loophole that most Argentines (and presumably expats who were aware of the tax and sought to avoid it) with overseas assets exploited, which was to fix their “domicile” as the address of their overseas property. With the loophole closed by an amendment to the legislation added at the last minute in the lower chamber of parliament, it appears to me, that now, strictly speaking, all expats with overseas financial and fixed assets over the first rung of the threshold (2,000,000 pesos) will have to either pay the tax or take the risk of avoiding it. The exception appears to be those who are in the country on working visas of less than five years, who have always had exemption and I see nothing in any of the commentary to suggest that exemption disappears.
I have obtained no professional advice on this; it is purely based on some research I have done in recent days since the matter appeared in the press. The tax changes are political and not directed at expats, but, on my reading, expats are collateral damage. One report I saw pointed out that this kind of wealth tax has been eliminated in most countries around the world because of the difficulty of collecting it, which goes to the point about whether AFIP has any means of really enforcing it/detecting overseas assets. Perhaps not (another report said that Migraciones and AFIP do not share information); nonetheless it is a risk for those either under or considering the Rentista category since in order to obtain the visa we declare and provide documentary proof to the government that we own property overseas. I am not sure that double taxation agreements between Argentina and foreign countries will give much relief, since they usually cover taxes common to both countries, and, as wealth taxes are rare the Bienes Personales tax is unlikely to be covered.