Inventories

Inventories consisted of the following (in millions):



	2018		2017
Materials, spares and supplies	$	446	$	563
Work-in-process	2,161		1,823
Finished goods	390		492
Total inventories	$	2,997	$	2,878

Work-in-process inventories at December 31, 2018 and 2017 included general and administrative costs of $53 million and $112 million. General and administrative costs incurred and recorded in inventories totaled $1.9 billion in 2018, $2.0 billion in 2017 and $1.9 billion in 2016. General and administrative costs charged to cost of sales from inventories totaled $2.0 billion in both 2018 and 2017 and $1.9 billion in 2016.

Costs incurred to fulfill a contract in advance of the contract being awarded are included in inventories as work-in-process if we determine that those costs relate directly to a contract or to an anticipated contract that we can specifically identify and contract award is probable, the costs generate or enhance resources that will be used in satisfying performance obligations, and the costs are recoverable (referred to as pre-contract costs). Pre-contract costs that are initially capitalized in inventory are generally recognized as cost of sales consistent with the transfer of products and services to the customer upon the receipt of the anticipated contract. All other pre-contract costs, including start-up costs, are expensed as incurred. As of December 31, 2018 and 2017, $443 million and $466 million of pre-contract costs were included in inventories.