We consider all of our investments classified as current assets to be available-for-sale. The following tables summarize our current investments as of the dates indicated:


	September 30, 2025
	Amortized Cost		Gross Unrealized				Estimated Fair Value
			Gains		Losses

	(In millions)
Corporate debt securities	$	2,574	$	35	$	9	$	2,600
Mortgage-backed securities	996		10		24		982
Asset-backed securities	396		3		3		396
Municipal securities	178		2		2		178
U.S. Treasury notes	22		—		—		22



Other	48		1		1		48
Total	$	4,214	$	51	$	39	$	4,226


	December 31, 2024
	Amortized Cost		Gross Unrealized				Estimated Fair Value
			Gains		Losses

	(In millions)
Corporate debt securities	$	2,769	$	10	$	35	$	2,744
Mortgage-backed securities	953		2		41		914
Asset-backed securities	435		2		6		431
Municipal securities	188		—		5		183
U.S. Treasury notes	5		—		—		5


Other	50		—		2		48
Total	$	4,400	$	14	$	89	$	4,325


	Amortized Cost		Estimated Fair Value

	(In millions)
Due in one year or less	$	649	$	646
Due after one year through five years	1,784		1,801
Due after five years through ten years	610		621
Due after ten years	1,171		1,158
Total	$	4,214	$	4,226

In the nine months ended September 30, 2025, and 2024, maturities and redemptions of available-for-sale securities amounted to $933 million and $786 million, respectively, and sales amounted to $84 million and $85 million, respectively. Gross realized gains and losses from sales of available-for-sale securities are calculated under the specific identification method and are included in investment income. Gross realized investment gains and losses were insignificant for the nine months ended September 30, 2025 and 2024.

The following table segregates those available-for-sale investments that have been in a continuous loss position for less than 12 months, and those that have been in a continuous loss position for 12 months or more as of September 30, 2025:


	In a Continuous Loss Position for Less than 12 Months					In a Continuous Loss Position for 12 Months or More
	Estimated Fair Value		Unrealized Losses		Total Number of Positions	Estimated Fair Value		Unrealized Losses		Total Number of Positions

	(Dollars in millions)
Corporate debt securities	$	—	$	—	—	$	493	$	9	243
Mortgage-backed securities	92		1		65	339		23		212
Asset-backed securities	—		—		—	87		3		44
Municipal securities	—		—		—	62		2		67

Other	—		—		—	14		1		17



Total	$	92	$	1	65	$	995	$	38	583


	In a Continuous Loss Position for Less than 12 Months					In a Continuous Loss Position for 12 Months or More
	Estimated Fair Value		Unrealized Losses		Total Number of Positions	Estimated Fair Value		Unrealized Losses		Total Number of Positions

	(Dollars in millions)
Corporate debt securities	$	811	$	10	541	$	935	$	25	449
Mortgage-backed securities	271		5		197	406		36		244
Asset-backed securities	84		1		48	143		5		73
Municipal securities	38		1		27	95		4		89


Other	—		—		—	15		2		16

Total	$	1,204	$	17	813	$	1,594	$	72	871

Pursuant to the regulations governing our state health plan subsidiaries, we maintain statutory deposits and deposits required by government authorities primarily in cash, cash equivalents, U.S. Treasury securities, and corporate debt securities. We also maintain restricted investments as protection against the insolvency of certain capitated providers. The use of these funds is limited as required by regulations in the various states in which we operate, or as needed in the event of insolvency of capitated providers. Therefore, such investments are reported as “Restricted investments” in the accompanying consolidated balance sheets.

We have the ability to hold these restricted investments until maturity and, as a result, we would not expect the value of these investments to decline significantly due to a sudden change in market interest rates. Our held-to-maturity restricted investments are carried at amortized cost, which approximates fair value. Such investments amounted to $300 million at September 30, 2025, of which $267 million will mature in one year or less, $28 million will mature in one through five years, and $5 million will mature after five years.