Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Current assets:
Cash and cash equivalents	$ 3,382.7	$ 3,008.5
Current portion of marketable securities	900.0	807.2
Inventory	1,949.0	2,168.1
Other current assets	1,168.3	1,123.3
Total current assets	9,190.4	8,974.1
Marketable securities	465.6	431.9
Property, plant and equipment, net	3,017.9	3,055.4
Operating lease assets	251.3	265.4
Intangible assets, net	9,053.5	9,178.5
Goodwill	6,488.7	6,491.1
Deferred tax asset	238.2	292.5
Investments and other assets	777.5	750.6
Total assets	29,483.1	29,439.5
Current liabilities:
Taxes payable	93.6	114.8
Accounts payable	358.5	432.0
Accrued expense and other	2,546.8	2,802.6
Total current liabilities	2,998.9	3,349.4
Notes payable	6,288.5	6,286.8
Deferred tax liability	483.5	507.6
Long-term operating lease liabilities	273.4	290.4
Other long-term liabilities	787.1	748.5
Total liabilities	10,831.4	11,182.7
Commitments, contingencies and guarantees
Biogen Inc. shareholders’ equity:
Preferred stock, par value $0.001 per share	0.0	0.0
Common stock, par value $0.0005 per share	0.1	0.1
Additional paid-in capital	896.7	863.1
Accumulated other comprehensive income (loss)	(140.2)	(182.0)
Retained earnings	20,872.2	20,552.7
Treasury stock, at cost	(2,977.1)	(2,977.1)
Total equity	18,651.7	18,256.8
Total liabilities and equity	29,483.1	29,439.5
Nonrelated Party
Current assets:
Accounts receivable, net of allowance for doubtful accounts of $3.0 and $3.0, respectively	1,369.2	1,342.4
Related Party
Current assets:
Accounts receivable, net of allowance for doubtful accounts of $3.0 and $3.0, respectively	$ 421.2	$ 524.6