The amortized cost and fair value of debt securities available for sale, with gross unrealized gains and losses, as of the dates indicated, follows:


December 31, 2025	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. government agencies and corporations	$	312,353	$	-	$	24,298	$	288,055
States and political subdivisions		177,453		-		23,736		153,717
Mortgage-backed securities		210,918		129		3,406		207,641
Corporate debt securities		5,505		-		541		4,964
Total securities available for sale	$	706,229	$	129	$	51,981	$	654,377


December 31, 2024	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. government agencies and corporations	$	351,136	$	-	$	40,012	$	311,124
States and political subdivisions		178,106		-		32,372		145,734
Mortgage-backed securities		143,747		24		5,473		138,298
Corporate debt securities		6,507		-		764		5,743
U.S. treasury		1,000		-		1		999
Total securities available for sale	$	680,496	$	24	$	78,622	$	601,898

The deferred tax asset for the net unrealized loss on securities available for sale was $10,889 as of December 31, 2025 and $16,506 as of December 31, 2024. The deferred tax asset along with other net deferred tax assets is included in other assets on the Consolidated Balance Sheets.

The amortized cost and fair value of single maturity securities available for sale, by contractual maturity as of the date indicated, are shown below. Mortgage-backed securities are categorized by final maturity. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.


December 31, 2025	Amortized Cost		Fair Value
Available for Sale:
Due in one year or less	$	23,709	$	23,484
Due after one year through five years		229,721		218,251
Due after five years through ten years		221,520		195,181
Due after ten years		231,279		217,461
Total securities available for sale	$	706,229	$	654,377

Information pertaining to securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position as of the dates indicated, follows:


	Less Than 12 Months				12 Months or More
December 31, 2025	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. government agencies and corporations	$	-	$	-	$	288,055	$	24,298
States and political subdivisions		1,680		364		151,652		23,372
Mortgage-backed securities		55,986		223		99,446		3,183
Corporate debt securities		-		-		4,964		541
Total temporarily impaired securities	$	57,666	$	587	$	544,117	$	51,394


	Less Than 12 Months				12 Months or More
December 31, 2024	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. government agencies and corporations	$	-	$	-	$	311,124	$	40,012
States and political subdivisions		885		118		144,849		32,254
Mortgage-backed securities		5,336		28		115,011		5,445
Corporate debt securities		-		-		5,743		764
U.S. treasury		-		-		999		1
Total temporarily impaired securities	$	6,221	$	146	$	577,726	$	78,476

The Company evaluates securities available for sale that are in unrealized loss positions to determine whether the impairment is due to credit-related factors or noncredit-related factors. At December 31, 2025, the Company had 522 securities with a fair value of $601,783 in an unrealized loss position. To evaluate credit risk, the Company considers payment history, risk ratings from external parties, financial statements for municipal and corporate securities, public statements from issuers and other available credible published sources in evaluating credit risk. No credit risk was found and no ACL on securities available for sale was recorded as of December 31, 2025 or December 31, 2024. The unrealized losses are attributable to noncredit-related factors, including changes in interest rates and other market conditions. The Company does not have the intent to sell any of these securities and believes that it is more likely than not that the Company will not have to sell any such securities before a recovery of cost. The contractual terms of the investments do not permit the issuers to settle the securities at a price less than the cost basis of the investments. The fair value is expected to recover as the securities approach their maturity date or repricing date or if market yields for such investments decline.

There were no sales of securities in 2025. During 2024, the Company sold securities acquired from FCB shortly after the acquisition date and no gain or loss was recognized. Information pertaining to realized gains and losses on sold securities for the period indicated follows:

The Company held restricted stock of $1,848 as of December 31, 2025 and December 31, 2024. Restricted stock is included in other assets. As a member of the Federal Reserve and the FHLB, NBB is required to maintain certain minimum investments in the common stock of those entities. Required levels of investment are based upon NBB’s capital and a percentage of qualifying assets. The Company purchases stock from or sells stock back to the correspondents based on their calculations. The stock is held by member institutions only and is not actively traded.

Redemption of FHLB stock is subject to certain limitations and conditions. At its discretion, the FHLB may declare dividends on the stock. In addition to dividends, NBB also benefits from its membership with FHLB through eligibility to borrow from the FHLB, using as collateral NBB’s capital stock investment in the FHLB and qualifying NBB real estate mortgage loans totaling $517,382 as of December 31, 2025. Management reviews for impairment based upon the ultimate recoverability of the cost basis of the FHLB stock, and as of December 31, 2025, management did not determine any impairment.

As of December 31, 2025 and 2024, securities with a carrying value of $654,370 and $536,260, respectively, were pledged to secure municipal deposits and Federal Reserve discount window borrowing capacity.