The amortized cost and estimated fair value of securities available for sale along with gross unrealized gains and losses as of the dates indicated are summarized as follows:


September 30, 2025	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. government agencies and corporations	$	322,309	$	-	$	26,437	$	295,872
States and political subdivisions		177,617		-		25,612		152,005
Mortgage-backed securities		181,664		32		4,033		177,663
Corporate debt securities		5,507		-		564		4,943
Total securities available for sale	$	687,097	$	32	$	56,646	$	630,483


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


	Less Than 12 Months				12 Months or More
September 30, 2025	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. government agencies and corporations	$	-	$	-	$	295,872	$	26,437
State and political subdivisions		-		-		151,620		25,612
Mortgage-backed securities		50,254		396		101,193		3,637
Corporate debt securities		-		-		4,943		564
Total temporarily impaired securities	$	50,254	$	396	$	553,628	$	56,250


	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
State 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. Consideration is given to the extent to which the fair value is less than cost, the financial condition and near-term prospects of the issuer, and the intent and ability of the Company to retain its investment in the security for a period of time sufficient to allow for any anticipated recovery in fair value.

At September 30, 2025, the Company had 534 securities with a fair value of $603,882 in an unrealized loss position. The Company reviews securities 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 losses were identified and no ACL on securities available for sale was recorded as of September 30, 2025 or December 31, 2024. The unrealized losses are attributed 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.

The amortized cost and fair value of securities available for sale at September 30, 2025, by contractual maturity, are shown below. 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. Mortgage-backed securities included in these totals are categorized by final maturity.


September 30, 2025	Amortized Cost		Fair Value
Available for Sale:
Due in one year or less	$	21,930	$	21,781
Due after one year through five years		224,100		213,221
Due after five years through ten years		223,667		196,423
Due after ten years		217,400		199,058
Total securities available for sale	$	687,097	$	630,483

Accrued interest receivable on securities, included in accrued interest receivable on the Consolidated Balance Sheets, totaled $3,320 at September 30, 2025 and $3,170 at December 31, 2024.

The deferred tax asset for the net unrealized loss on securities available for sale was $11,889 as of September 30, 2025 and $16,506 as of December 31, 2024. The deferred tax asset is included in other assets on the Consolidated Balance Sheets.

There were no sales of securities during the nine months ended September 30, 2025 and 2024.

The Company held restricted stock of $3,748 as of September 30, 2025 and $1,848 as of December 31, 2024 included in other assets on the Consolidated Balance Sheets. As a member of the Federal Reserve and the Federal Home Loan Bank of Atlanta (“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 $515,009 at September 30, 2025. The Company’s management reviews for impairment based upon the ultimate recoverability of the cost basis of the FHLB stock, and at September 30, 2025, did not determine any impairment.