Financial Post:  Obamacare Could Cost Some Canadians a Lot of Money:

In the wee hours of Jan. 1, 2013, as most of the country was catching
some shuteye after the previous night’s New Year’s Eve festivities, the
U.S. Senate passed the American Taxpayer Relief Tax Act of 2012 or, as
some people refer to it, the “fiscal cliff” act.

The legislation contains changes to tax rules which may be relevant
to the estimated one million U.S. citizens living in Canada. Under U.S.
law, citizens are required to file an income tax return reporting
worldwide income no matter where they reside. Most countries, including
Canada, have a residency-based taxation system rather than a
citizenship-based system.

In the majority of cases, however, U.S. citizens don’t end up owing
U.S. federal tax due to offsetting foreign tax credits. For example,
under the new legislation, U.S. high-income earners now face a top tax
rate of 39.6% for income over $400,000, an increase from 2012’s top 35%
rate. By comparison, Canada’s top marginal rate is 29% and kicks in at
income of roughly $135,000 in 2013. But when you add in provincial
taxes, combined top marginal rates range from 39% to 50%. This means
that in nearly all cases, there will be enough Canadian taxes paid to
offset any U.S. tax liability owing.

But for those U.S. persons making more than $200,000 in 2013, a
separate piece of legislation, the Patient Protection and Affordable
Care Act, known informally as “Obamacare,” could prove to be a real cost
to some Canadians. The PPACA included a new measure, effective for
2013, called the net investment income tax (NIIT), which imposes a 3.8%
surtax on net investment income, including interest, dividends and
capital gains.

The problem for dual income tax filers, according to an alert issued
by U.S. tax lawyer James Gifford of Moody’s LLP in Calgary, is that
“foreign taxes most likely will not be creditable against the 3.8%
Obamacare tax on net investment income.” This means that high-income
Canadians may have to start writing a cheque to Uncle Sam for the first
time in 2013.