The amortized cost and fair value of securities available-for-sale and held-to-maturity at September 30, 2023 and December 31, 2022 are summarized as follows (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
September 30, 2023:
Securities available-for-sale:
U.S. Treasury securities	$	732,128	$	1	$	2,973	$	729,156
U.S. Government agency securities	284,739		—		29,634		255,105
Mortgage-backed securities	1,051,931		131		164,155		887,907
State and municipal securities	1,547,266		3,142		139,285		1,411,123
Asset-backed securities	178,213		2		14,753		163,462
Corporate notes and other	471,984		72		55,112		416,944
	$	4,266,261	$	3,348	$	405,912	$	3,863,697
Securities held-to-maturity:
U.S. Treasury securities	$	90,417	$	—	$	5,416	$	85,001
U.S. Government agency securities	364,641		—		29,030		335,611
Mortgage-backed securities	386,095		—		50,562		335,533
State and municipal securities	1,893,923		—		324,216		1,569,707
Asset-backed securities	198,650		—		18,645		180,005
Corporate notes and other	86,561		—		11,186		75,375
	$	3,020,287	$	—	$	439,055	$	2,581,232
Allowance for credit losses - securities held-to-maturity	(1,708)
Securities held-to-maturity, net of allowance for credit losses	$	3,018,579


December 31, 2022:
Securities available-for-sale:
U.S. Treasury securities	$	196,151	$	—	$	1,967	$	194,184
U.S. Government agency securities	432,475		—		36,318		396,157
Mortgage-backed securities	1,114,948		211		143,583		971,576
State and municipal securities	1,478,310		12,553		78,557		1,412,306
Asset-backed securities	134,386		—		16,983		117,403
Corporate notes and other	515,221		41		48,018		467,244
	$	3,871,491	$	12,805	325,426		$	3,558,870
Securities held-to-maturity:
U.S Treasury securities	$	92,738	$	—	$	6,472	$	86,266
U.S. Government agency securities	374,255		—		27,860		346,395
Mortgage-backed securities	413,119		52		41,593		371,578
State and municipal securities	1,927,778		2,216		233,564		1,696,430
Asset-backed securities	184,241		—		18,573		165,668
Corporate notes	88,527		—		9,918		78,609
	$	3,080,658	$	2,268	$	337,980	$	2,744,946
Allowance for credit losses - securities held-to-maturity	(1,608)
Securities held-to-maturity, net of allowance for credit losses	$	3,079,050

During the quarters ended March 31, 2022, March 31, 2020 and September 30, 2018, Pinnacle Financial transferred, at fair value, $1.1 billion, $873.6 million and $179.8 million, respectively, of securities from the available-for-sale portfolio to the held-to-maturity portfolio. The related net unrealized after tax losses of $1.5 million, net unrealized after tax gains of $69.0 million and net unrealized after tax losses of $2.2 million, respectively, remained in accumulated other comprehensive income (loss) and are being amortized over the remaining life of the transferred securities, offsetting the related amortization of discount or premium on the transferred securities. No gains or losses were recognized at the time of the transfer. At September 30, 2023, approximately $1.9 billion of securities within Pinnacle Financial's investment portfolio were pledged to secure either public funds and other deposits or securities sold under agreements to repurchase. At September 30, 2023, repurchase agreements comprised of secured borrowings totaled $196.0 million and were secured by $196.0 million of pledged U.S. government agency securities, mortgage-backed securities, municipal

securities, asset-backed securities and corporate debentures. As the fair value of securities pledged to secure repurchase agreements may decline, Pinnacle Financial regularly evaluates its need to pledge additional securities to the customers with whom it has entered into the repurchase agreements for the customers to remain adequately secured.

The amortized cost and fair value of debt securities as of September 30, 2023 by contractual maturity is shown below. Actual maturities may differ from contractual maturities of mortgage- and asset-backed securities since the mortgages and assets underlying the securities may be called or prepaid with or without penalty. Therefore, these securities are not included in the maturity categories in the following summary (in thousands):


	Available-for-sale				Held-to-maturity
September 30, 2023:	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	20,932	$	22,591	$	19,901	$	19,059
Due in one year to five years	121,345		128,684		396,635		367,156
Due in five years to ten years	623,763		550,333		132,910		117,293
Due after ten years	2,270,077		2,110,720		1,886,096		1,562,186
Mortgage-backed securities	1,051,931		887,907		386,095		335,533
Asset-backed securities	178,213		163,462		198,650		180,005
	$	4,266,261	$	3,863,697	$	3,020,287	$	2,581,232


	Investments with an Unrealized Loss of less than 12 months				Investments with an Unrealized Loss of 12 months or longer				Total Investments with an Unrealized Loss
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
At September 30, 2023
U.S. Treasury securities	$	548,685	$	2,357	$	172,773	$	616	$	721,458	$	2,973
U.S. Government agency securities	26,468		280		228,637		29,354		255,105		29,634
Mortgage-backed securities	53,755		2,253		801,474		161,902		855,229		164,155
State and municipal securities	221,897		24,286		989,360		114,999		1,211,257		139,285
Asset-backed securities	69,397		1,283		93,719		13,470		163,116		14,753
Corporate notes	10,996		222		384,950		54,890		395,946		55,112
Total temporarily-impaired securities	$	931,198	$	30,681	$	2,670,913	$	375,231	$	3,602,111	$	405,912

At December 31, 2022
U.S. Treasury securities	$	192,188	$	1,963	$	1,997	$	4	$	194,185	$	1,967
U.S. Government agency securities	46,062		2,224		350,094		34,094		396,156		36,318
Mortgage-backed securities	390,014		34,106		570,601		109,477		960,615		143,583
State and municipal securities	568,691		18,863		304,451		59,694		873,142		78,557
Asset-backed securities	513		5		116,442		16,978		116,955		16,983
Corporate notes	259,453		20,260		207,326		27,758		466,779		48,018
Total temporarily-impaired securities	$	1,456,921	$	77,421	$	1,550,911	$	248,005	$	3,007,832	$	325,426

The applicable dates for determining when available-for-sale securities were in an unrealized loss position were September 30, 2023 and December 31, 2022. As such, it is possible that an available-for-sale security had a market value less than its amortized cost on other days during the twelve-month periods ended September 30, 2023 and December 31, 2022, but is not in the "Investments with an Unrealized Loss of less than 12 months" category above.

As shown in the tables above, at September 30, 2023, Pinnacle Financial had approximately $405.9 million in unrealized losses on approximately $3.6 billion of available-for-sale securities. For any securities classified as available-for-sale that are in an unrealized loss position at the balance sheet date, Pinnacle Financial assesses whether or not it intends to sell the security, or more likely than not will be required to sell the security, before recovery of its amortized cost basis which would require a write-down to fair value through net income. Because Pinnacle Financial currently does not intend to sell those available-for-sale securities that have

an unrealized loss at September 30, 2023, and it is not more-likely-than-not that Pinnacle Financial will be required to sell the securities before recovery of their amortized cost bases, which may be maturity, Pinnacle Financial has determined that no write-down is necessary. In addition, Pinnacle Financial evaluates whether any portion of the decline in fair value of available-for-sale securities is the result of credit deterioration, which would require the recognition of an allowance for credit losses. Such evaluations consider the extent to which the amortized cost of the security exceeds its fair value, changes in credit ratings and any other known adverse conditions related to the specific security. The unrealized losses associated with available-for-sale securities at September 30, 2023 are driven by changes in interest rates and are not due to the credit quality of the securities, and accordingly, no allowance for credit losses is considered necessary related to available-for-sale securities at September 30, 2023. These securities will continue to be monitored as a part of Pinnacle Financial's ongoing evaluation of credit quality. Management evaluates the financial performance of the issuers on a quarterly basis to determine if it is probable that the issuers can make all contractual principal and interest payments.

The allowance for credit losses on held-to-maturity securities is measured on a collective basis by major security type. Pinnacle Financial has a zero loss expectation for U.S. treasury securities in addition to U.S. Government agency securities and mortgage-backed securities issued by Ginnie Mae, Fannie Mae and Freddie Mac, and accordingly, no allowance for credit losses is estimated for these securities. Credit losses on held-to-maturity state and municipal securities and corporate notes and other securities are estimated using third-party probability of default and loss given default models driven primarily by macroeconomic factors over a reasonable and supportable period of eighteen months with a twelve month reversion to average loss factors. At September 30, 2023 and December 31, 2022, the estimated allowance for credit losses on these held-to-maturity securities was $1.7 million and $1.6 million, respectively, with the change driven largely by changes in macroeconomic forecasts.

Pinnacle Financial utilizes bond credit ratings assigned by third party ratings agencies to monitor the credit quality of debt securities held-to-maturity. At September 30, 2023, all debt securities classified as held-to-maturity were rated A or higher by the ratings agencies. Updated credit ratings are obtained as they become available from the ratings agencies.

Periodically, available-for-sale securities may be sold or the composition of the portfolio realigned to improve yields, quality or marketability, or to implement changes in investment or asset/liability strategy, including maintaining collateral requirements and raising funds for liquidity purposes or preparing for anticipated changes in market interest rates. Additionally, if an available-for-sale security loses its investment grade or tax-exempt status, the underlying credit support is terminated or collection otherwise becomes uncertain based on factors known to management, Pinnacle Financial will consider selling the security, but will review each security on a case-by-case basis as these factors become known. During the three and nine months ended September 30, 2023, $129.6 million and $303.1 million of available-for-sale securities were sold, respectively, resulting in gross realized gains of $289,000 and $302,000 and gross realized losses of $10.0 million and $20.0 million, respectively. During the three months ended September 30, 2022, $26.6 million of available-for-sale securities were sold resulting in gross realized gains of $292,000 and gross realized losses of $76,000, respectively. During the nine months ended September 30, 2022, $29.5 million of available-for-sale securities were sold resulting in gross realized gains of $292,000 and gross realized losses of $136,000.

Pinnacle Financial has entered into various fair value hedging transactions to mitigate the impact of changing interest rates on the fair values of available-for-sale securities. See Note 9. Derivative Instruments for disclosure of the gains and losses recognized on derivative instruments and the cumulative fair value hedging adjustments to the carrying amount of the hedged securities.