United states securities and exchange commission

Table of Contents
BIOGEN INC. AND SUBSIDIARIES
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)
F- 39
12.   Indebtedness
Our indebtedness is summarized as follows:
 
As of December 31,
(In millions)
2017
2016
Current portion:
Notes payable to Fumedica
$
3.2
$
3.0
Financing arrangement for the purchase of the RTP facility
—
1.7
Current portion of notes payable and other financing arrangements
$
3.2
$
4.7
Non-current portion:
6.875% Senior Notes due March 1, 2018
$
—
$
558.5
2.900% Senior Notes due September 15, 2020
1,482.4
1,485.3
3.625% Senior Notes due September 15, 2022
994.3
993.2
4.050% Senior Notes due September 15, 2025
1,736.3
1,734.8
5.200% Senior Notes due September 15, 2045
1,722.0
1,721.5
Notes payable to Fumedica
—
3.0
Financing arrangement for the purchase of the RTP facility
—
16.4
Non-current portion of notes payable and other financing arrangements
$
5,935.0
$
6,512.7
6.875% Senior Notes due March 1, 2018
On March 4, 2008, we issued $550.0 million aggregate principal amount of 6.875% Senior Notes due 
March 1, 2018 at 99.184% of par. These notes were senior unsecured obligations. We also entered into interest 
rate swap contracts where we received a fixed rate and paid a variable rate. These contracts were terminated in 
December 2008. Upon termination of these contracts, the carrying amount of these notes were increased by $62.8 
million with this amount being amortized using the effective interest rate method over the remaining life of the 
Senior Notes and recognized as a reduction of interest expense.
In November 2017 we redeemed these notes prior to their maturity and recognized a net charge of $5.2 million 
upon the extinguishment of these notes. This charge, which was recognized in interest expense in other income 
(expense) net in our consolidated statements of income for the year ended December 31, 2017, reflects the 
payment of a $7.7 million early call premium and the write off of remaining unamortized original debt issuance costs 
and discount balances, partially offset by a $2.9 million gain related to the remaining unamortized balance of the 
interest rate swap liability discussed above.
2015 Senior Notes
The following is a summary of our principal indebtedness as of December 31, 2017:
•  $1.5 billion aggregate principal amount of 2.90% Senior Notes due September 15, 2020, valued at 99.792% of 
par;
•  $1.0 billion aggregate principal amount of 3.625% Senior Notes due September 15, 2022, valued at 99.920% 
of par;
•  $1.75 billion aggregate principal amount of 4.05% Senior Notes due September 15, 2025, valued at 99.764% 
of par; and
•  $1.75 billion aggregate principal amount of 5.20% Senior Notes due September 15, 2045, valued at 99.294% 
of par.
The costs associated with these offerings of approximately $47.5 million have been recorded as a reduction to 
the carrying amount of the debt in our consolidated balance sheet. These costs along with the discounts will be 
amortized as additional interest expense using the effective interest rate method over the period from issuance 
through maturity. 
These notes are senior unsecured obligations. These Senior Notes may be redeemed at our option at any time 
at 100% of the principal amount plus accrued interest and a specified make-whole amount. These Senior Notes 

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Table of Contents
BIOGEN INC. AND SUBSIDIARIES
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)
F- 40
contain a change of control provision that may require us to purchase the notes at a price equal to 101% of the 
principal amount plus accrued and unpaid interest to the date of purchase under certain circumstances.
In connection with the 2.90% Senior Notes offering due in 2020, we entered into interest rate swap contracts. 
The carrying value of the 2.90% Senior Notes includes approximately $10.1 million related to changes in the fair 
value of these contracts. For additional information on our interest rate contracts, please read Note 10, Derivative 
Instruments, to these consolidated financial statements.
Notes Payable to Fumedica
In connection with our 2006 distribution agreement with Fumedica, we issued notes totaling 61.4 million Swiss 
Francs that are payable to Fumedica in varying amounts from June 2008 through June 2018. Our remaining note 
payable to Fumedica, payable in June 2018, had a carrying value of 3.1 million Swiss Francs ($3.2 million) and 6.2 
million Swiss Francs ($6.0 million) as of December 31, 2017 and 2016, respectively.
Credit Facility
In August 2015 we entered into a $1.0 billion, five-year senior unsecured revolving credit facility under which 
we are permitted to draw funds for working capital and general corporate purposes. The terms of the revolving credit 
facility include a financial covenant that requires us not to exceed a maximum consolidated leverage ratio. As of 
December 31, 2017, we had no outstanding borrowings and were in compliance with all covenants under this facility.
Financing Arrangement
During 2015 we recorded a financing obligation in relation to the amendment of our lease agreement for 
Eisai's oral solid dose products manufacturing facility in RTP, NC. In December 2017 we completed the purchase of 
this facility for $17.2 million and derecognized the remaining unamortized portion of the financing obligation from 
our consolidated balance sheet as of that date. For additional information on this transaction, please read Note 11, 
Property, Plant and Equipment, to these consolidated financial statements.
Debt Maturity
The total gross payments, excluding our financing arrangement, due under our debt arrangements are as 
follows:
(In millions)
As of December 31, 2017
2018
$
3.2
2019
—
2020
1,500.0
2021
—
2022
1,000.0
2023 and thereafter
3,500.0
Total
$
6,003.2
The fair value of our debt is disclosed in Note 8, Fair Value Measurements, to these consolidated financial 
statements.
13.    Equity
Preferred Stock
We have 8.0 million shares of Preferred Stock authorized, of which 1.75 million shares are authorized as 
Series A, 1.0 million shares are authorized as Series X junior participating and 5.25 million shares are 
undesignated. Shares may be issued without a vote or action of shareholders from time to time in classes or series 
with the designations, powers, preferences, and the relative, participating, optional or other special rights of the 
shares of each such class or series and any qualifications, limitations or restrictions thereon as set forth in the 
instruments governing such shares. Any such Preferred Stock may rank prior to common stock as to dividend rights, 
liquidation preference or both, and may have full or limited voting rights and may be convertible into shares of 
common stock. No shares of Preferred Stock were issued and outstanding during 2017, 2016 and 2015.

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