Schedule II - Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2021

Valuation And Qualifying Accounts [Abstract]

Schedule II - Valuation and Qualifying Accounts

MKS Instruments, Inc.

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS

(in millions)

			Additions
Description	Balance at Beginning of Year		Acquisition Beginning Balance		Charged to Costs and Expenses			Charged to Other Accounts		Deductions & Write-offs			Balance at End of Year
Allowance for doubtful accounts:
Years ended December 31,
2021	$	2.0	$	—	$	1.3		$	—	$	0.3		$	3.6
2020	$	1.8	$	—	$	0.1		$	—	$	0.1		$	2.0
2019	$	5.2	$	0.2	$	(0.7	)	$	—	$	(2.9	)	$	1.8

			Additions
Description	Balance at Beginning of Year		Acquisition Beginning Balance		Charged to Costs and Expenses			Charged to Other Accounts		Deductions & Write-offs			Balance at End of Year
Allowance for sales returns:
Years ended December 31,
2021	$	1.8	$	—	$	(0.1	)	$	—	$	(0.1	)	$	1.6
2020	$	1.4	$	—	$	0.3		$	—	$	0.1		$	1.8
2019	$	1.0	$	—	$	0.2		$	—	$	0.2		$	1.4

			Additions
Description	Balance at Beginning of Year		Acquisition Beginning Balance		Charged to Costs and Expenses		Charged to Other Accounts		Deductions			Balance at End of Year
Valuation allowance on deferred tax asset:
Years ended December 31,
2021	$	30.6	$	—	$	2.3	$	—	$	(6.7	)	$	26.2
2020	$	27.4	$	—	$	4.2	$	—	$	(1.0	)	$	30.6
2019	$	17.9	$	5.9	$	4.9	$	—	$	(1.3	)	$	27.4