The Company invests in agency securities, corporate securities, asset-backed securities and other securities. The following is a summary of amounts recorded on the Consolidated Balance Sheet for marketable securities (current and non-current).

		December 31,		December 31,
(Millions)		2014		2013

U.S. government agency securities		$	67	$	103
Foreign government agency securities			75		30
Corporate debt securities			241		143
Commercial paper			―		60
Certificates of deposit/time deposits			41		20
U.S. municipal securities			―		2
Asset-backed securities:
	Automobile loan related		122		287
	Credit card related		59		52
	Equipment lease related		21		30
	Other		―		29
Asset-backed securities total			202		398

Current marketable securities		$	626	$	756

U.S. government agency securities		$	41	$	131
Foreign government agency securities			20		95
Corporate debt securities			378		638
Certificates of deposit/time deposits			―		20
U.S. treasury securities			38		49
U.S. municipal securities			15		―
Auction rate securities			―		11
Asset-backed securities:
	Automobile loan related		160		298
	Credit card related		103		128
	Equipment lease related		27		37
	Other		46		46
Asset-backed securities total			336		509

Non-current marketable securities		$	828	$	1,453

Total marketable securities		$	1,454	$	2,209

Classification of marketable securities as current or non-current is dependent upon management's intended holding period, the security's maturity date and liquidity considerations based on market conditions. If management intends to hold the securities for longer than one year as of the balance sheet date, they are classified as non-current. At December 31, 2014, gross unrealized losses totaled approximately $1 million (pre-tax), while gross unrealized gains totaled approximately $1 million (pre-tax). At December 31, 2013, gross unrealized losses totaled approximately $5 million (pre-tax), while gross unrealized gains totaled approximately $1 million (pre-tax). Refer to Note 5 for a table that provides the net realized gains (losses) related to sales or impairments of debt and equity securities, which includes marketable securities. The gross amounts of the realized gains or losses were not material. Cost of securities sold use the first in, first out (FIFO) method. Since these marketable securities are classified as available-for-sale securities, changes in fair value will flow through other comprehensive income, with amounts reclassified out of other comprehensive income into earnings upon sale or “other-than-temporary” impairment.

3M reviews impairments associated with its marketable securities in accordance with the measurement guidance provided by ASC 320, Investments-Debt and Equity Securities, when determining the classification of the impairment as “temporary” or “other-than-temporary”. A temporary impairment charge results in an unrealized loss being recorded in the other comprehensive income component of shareholders' equity. Such an unrealized loss does not reduce net income attributable to 3M for the applicable accounting period because the loss is not viewed as other-than-temporary. The factors evaluated to differentiate between temporary and other-than-temporary include the projected future cash flows, credit ratings actions, and assessment of the credit quality of the underlying collateral, as well as other factors.

The balance at December 31, 2014, for marketable securities by contractual maturity are shown below. Actual maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties.

(Millions)	December 31, 2014

Due in one year or less	$	367
Due after one year through five years		1,064
Due after five years through ten years		8
Due after ten years		15

Total marketable securities	$	1,454

3M has a diversified marketable securities portfolio of $1.454 billion as of December 31, 2014. Within this portfolio, current and long-term asset-backed securities (estimated fair value of $538 million) primarily include interests in automobile loans, credit cards and equipment leases. 3M's investment policy allows investments in asset-backed securities with minimum credit ratings of Aa2 by Moody's Investors Service or AA by Standard & Poor's or Fitch Ratings or DBRS. Asset-backed securities must be rated by at least two of the aforementioned rating agencies, one of which must be Moody's Investors Service or Standard & Poor's. At December 31, 2014, all asset-backed security investments were in compliance with this policy. Approximately 96.6 percent of all asset-backed security investments were rated AAA or A-1+ by Standard & Poor's and/or Aaa or P-1 by Moody's Investors Service and/or AAA or F1+ by Fitch Ratings. Interest rate risk and credit risk related to the underlying collateral may impact the value of investments in asset-backed securities, while factors such as general conditions in the overall credit market and the nature of the underlying collateral may affect the liquidity of investments in asset-backed securities. 3M does not currently expect risk related to its holding in asset-backed securities to materially impact its financial condition or liquidity.