In order to determine net cash provided by operating activities, net income (loss) is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions):


	Year Ended December 31,
	2021		2020		2019
Decrease (increase) in current assets:
Receivables, net	$	(4,382)	$	2,773	$	(1,041)
Inventories	(253)		1,007		(385)

Prepaid expenses and other	(22)		101		—
Increase (decrease) in current liabilities:
Accounts payable	6,301		(4,068)		1,534
Accrued expenses	253		48		(27)
Taxes other than income taxes payable	104		37		60
Income taxes payable	224		(243)		153
Changes in current assets and current liabilities	$	2,225	$	(345)	$	294

Changes in current assets and current liabilities for the year ended December 31, 2021 were primarily due to the following:

•The increase in receivables was primarily due to an increase in refined petroleum product prices in December 2021 compared to December 2020 combined with an increase in refined petroleum product sales volumes, partially offset by a decrease in income taxes receivable primarily associated with the receipt of a $962 million refund related to our U.S. federal income tax return for 2020; and

•The increase in accounts payable was primarily due to an increase in crude oil and other feedstock prices in December 2021 compared to December 2020 combined with an increase in crude oil and other feedstock volumes purchased.

Changes in current assets and current liabilities for the year ended December 31, 2020 were primarily due to the following:

•The decrease in receivables was due to (i) a decrease of $3.3 billion as a result of a decrease in sales volumes combined with a decrease in the prices of our products in December 2020 compared to December 2019 and (ii) the collection of $449 million for a blender’s tax credit receivable attributable to volumes blended during 2019 and 2018, partially offset by an increase in income taxes receivable of $1.0 billion primarily due to the recognition of a current income tax benefit;

•The decrease in inventories was primarily due to a reduction of higher-cost inventory volumes in our Refining segment in December 2020 compared to December 2019; and

•The decrease in accounts payable was due to a decrease in crude oil and other feedstock volumes purchased combined with a decrease in crude oil and other feedstock prices in December 2020 compared to December 2019.

Changes in current assets and current liabilities for the year ended December 31, 2019 were primarily due to the following:

•The increase in receivables was due to (i) an increase in the prices of our products and sales volumes in December 2019 compared to December 2018 and (ii) a receivable of $449 million for the blender’s tax credit attributable to volumes blended during 2019 and 2018, partially offset by an income tax refund of $348 million, including interest, associated with the settlement of the combined audit related to our U.S. federal income tax returns for 2010 and 2011;

•The increase in inventories was due to an increase in inventory unit prices and higher inventory levels in December 2019 compared to December 2018;

•The increase in accounts payable was due to an increase in crude oil and other feedstock prices in December 2019 compared to December 2018 combined with an increase in crude oil and other feedstock volumes purchased and the timing of payments of invoices; and

•The increase in income taxes payable was primarily due to higher pre-tax income in the fourth quarter of 2019.


	Year Ended December 31,
	2021		2020		2019
Interest paid in excess of amount capitalized, including interest on finance leases	$	598	$	526	$	452
Income taxes paid (refunded), net (see Note 16)	(842)		203		(116)

Supplemental cash flow information related to our operating and finance leases was as follows (in millions):


	Year Ended December 31,
	2021				2020				2019
	Operating Leases		Finance Leases		Operating Leases		Finance Leases		Operating Leases		Finance Leases
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows	$	397	$	72	$	444	$	97	$	441	$	50
Investing cash flows	1		—		1		—		1		—
Financing cash flows	—		135		—		80		—		40
Changes in lease balances resulting from new and modified leases (a)	451		378		263		950		1,756		239

(a)Noncash activity for the year ended December 31, 2020 primarily included approximately $800 million for a finance lease ROU asset and related liability recognized in connection with the terminaling agreement with MVP described in Note 6. Noncash activity for the year ended December 31, 2019 included $1.3 billion for operating lease ROU assets and related liabilities recorded on January 1, 2019 upon adoption of FASB Accounting Standards Codification Topic 842, “Leases,” (Topic 842).

There were no significant noncash investing and financing activities during the years ended December 31, 2021 and 2020, except as noted in the table above.

Prior to our adoption of Topic 842 in 2019, we were considered the accounting owner of the MVP Terminal during its construction due to our membership interest in MVP and because we determined that the terminaling agreement was a capital lease. Accordingly, as of December 31, 2018, we had recorded an asset of $539 million in property, plant, and equipment representing 100 percent of the construction costs incurred by MVP, as well as capitalized interest incurred by us, and a long-term liability of $292 million payable to Magellan.

On January 1, 2019, as a result of our adoption of Topic 842, we derecognized the asset and liability related to MVP discussed above and recorded our equity investment in MVP of $247 million, which is included in “deferred charges and other assets, net.” These amounts were noncash investing and financing activities for the year ended December 31, 2019.