Inventories

Inventories at March 31, 2017 and December 31, 2016 were as follows (in millions):



	March 31, 2017			December 31, 2016
Raw materials and supplies	$	148.8		$	149.6
Work-in-process	855.5			837.9
Finished goods	160.0			161.7
Total inventories at current cost	1,164.3			1,149.2
Adjustment from current cost to LIFO cost basis	89.3			97.3
Inventory valuation reserves	(157.6		)	(169.0		)
Progress payments	(44.1		)	(40.5		)
Total inventories, net	$	1,051.9		$	1,037.0

Inventories are stated at the lower of cost (last-in, first-out (LIFO), first-in, first-out (FIFO), and average cost methods) or market, less progress payments. Most of the Company’s inventory is valued utilizing the LIFO costing methodology. Inventory of the Company’s non-U.S. operations is valued using average cost or FIFO methods. Due to deflationary impacts primarily related to raw materials, the carrying value of the Company’s inventory as valued on LIFO exceeds current replacement cost, and based on a lower of cost or market value analysis, a net realizable value (NRV) inventory reserve is required. Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV inventory reserves were as follows (in millions):



	Three months ended March 31,
	2017			2016
LIFO benefit (charge)	$	(8.1	)	$	(0.3	)
NRV benefit (charge)	8.1			0.3
Net cost of sales impact	$	—		$	—

Results for the first quarter of 2016 included $10.0 million in inventory valuation charges related to the market-based valuation of titanium products.