IRS Seeks More Taxes From Amgen, Adding to $10.7 Billion Dispute

Amgen Inc. is facing IRS demands for additional taxes in its dispute with the agency over profits in Puerto Rico, beyond the $10.7 billion that the company has previously acknowledged it may owe.

The biotechnology giant said Thursday that the IRS has proposed “significant adjustments” to its tax bills from 2016 to 2018. The approach is similar to Amgen’s existing dispute with the agency in Tax Court over which it could owe taxes, interest and penalties for 2010 to 2015 over what the IRS contends is Amgen’s shifting of US profits to Puerto Rico to enjoy the territory’s lower tax ...