Securities

9 Months Ended

Sep. 30, 2025

Available for Sale Securities

The amortized cost, gross unrealized gains and losses, allowance for credit losses (“ACL”) and fair value of available for sale (“AFS”) securities as of the dates indicated were as follows:


	As of September 30, 2025
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
	(In thousands)
Debt securities:
Government-sponsored residential mortgage-backed securities	$	2,756,870	$	16,384	$	(254,951)	$	—	$	2,518,303
Government-sponsored commercial mortgage-backed securities	1,156,696		8,737		(102,382)		—		1,063,051
U.S. Treasury securities	50,034		292		—		—		50,326
State and municipal bonds and obligations	191,741		15		(12,805)		—		178,951
	$	4,155,341	$	25,428	$	(370,138)	$	—	$	3,810,631


	As of December 31, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
	(In thousands)
Debt securities:
Government-sponsored residential mortgage-backed securities	$	3,099,328	$	—	$	(537,433)	$	—	$	2,561,895
Government-sponsored commercial mortgage-backed securities	1,362,519		—		(201,408)		—		1,161,111
U.S. Agency bonds	19,608		—		(1,936)		—		17,672
U.S. Treasury securities	99,784		—		(2,165)		—		97,619
State and municipal bonds and obligations	197,405		—		(14,104)		—		183,301
	$	4,778,644	$	—	$	(757,046)	$	—	$	4,021,598

The Company did not record a provision for credit losses on any AFS securities for either the three and nine months ended September 30, 2025 or 2024. Accrued interest receivable on AFS securities totaled $12.0 million and $8.9 million as of September 30, 2025 and December 31, 2024, respectively, and is included within other assets on the Consolidated Balance Sheets. The Company did not record any write-offs of accrued interest receivable on AFS securities during either the three and nine months ended September 30, 2025 or 2024. No AFS securities held by the Company were delinquent on contractual payments as of September 30, 2025 or December 31, 2024, nor were any AFS securities placed on non-accrual status during the nine and twelve-month periods then ended.

The following table summarizes gross realized gains and losses from sales of AFS securities for the periods indicated:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
	(In thousands)
Gross realized gains from sales of AFS securities	$	—	$	—	$	—	$	—
Gross realized losses from sales of AFS securities	—		—		(269,638)		(7,557)
Net losses from sales of AFS securities	$	—	$	—	$	(269,638)	$	(7,557)

Information pertaining to AFS securities with gross unrealized losses as of September 30, 2025 and December 31, 2024, for which the Company did not recognize a provision for credit losses under the current expected credit loss methodology (“CECL”), aggregated by investment category and length of time that individual securities had been in a continuous loss position, is as follows:


	As of September 30, 2025
		Less than 12 Months				12 Months or Longer				Total
	# of Holdings	Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value
	(Dollars in thousands)
Government-sponsored residential mortgage-backed securities	291	$	—	$	—	$	254,951	$	1,548,459	$	254,951	$	1,548,459
Government-sponsored commercial mortgage-backed securities	149	—		—		102,382		612,555		102,382		612,555
U.S. Treasury securities	—	—		—		—		—		—		—
State and municipal bonds and obligations	213	1		2,131		12,804		165,567		12,805		167,698
	653	$	1	$	2,131	$	370,137	$	2,326,581	$	370,138	$	2,328,712


	As of December 31, 2024
		Less than 12 Months				12 Months or Longer				Total
	# of Holdings	Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value
	(Dollars in thousands)
Government-sponsored residential mortgage-backed securities	324	$	9	$	113,326	$	537,424	$	2,448,569	$	537,433	$	2,561,895
Government-sponsored commercial mortgage-backed securities	187	27		86,201		201,381		1,074,910		201,408		1,161,111
U.S. Agency bonds	1	—		—		1,936		17,672		1,936		17,672
U.S. Treasury securities	6	—		—		2,165		97,619		2,165		97,619
State and municipal bonds and obligations	238	819		19,361		13,285		163,940		14,104		183,301
	756	$	855	$	218,888	$	756,191	$	3,802,710	$	757,046	$	4,021,598

The Company does not intend to sell these investments and has determined based upon available evidence that it is not more-likely-than-not that the Company will be required to sell each security before the expected recovery of its amortized cost basis. As a result, the Company did not recognize an ACL on these investments as of either September 30, 2025 or December 31, 2024.

The causes of the impairments listed in the tables above by category are as follows as of September 30, 2025 and December 31, 2024:

•Government-sponsored mortgage-backed securities, U.S. Agency bonds and U.S. Treasury securities – The securities with unrealized losses in these portfolios have contractual terms that generally do not permit the issuer to settle the security at a price less than the current par value of the investment. The decline in market value of these securities is attributable to changes in interest rates and not credit quality. Additionally, these securities are implicitly guaranteed by the U.S. government or one of its agencies.

•State and municipal bonds and obligations – The securities with unrealized losses in this portfolio have contractual terms that generally do not permit the issuer to settle the security at a price less than the current par value of the investment. The decline in market value of these securities is attributable to changes in interest rates and not credit quality.

Held to Maturity Securities

The amortized cost, gross unrealized gains and losses, allowance for credit losses and fair value of held to maturity (“HTM”) securities as of the dates indicated were as follows:


	As of September 30, 2025
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
	(In thousands)
Debt securities:
Government-sponsored residential mortgage-backed securities	$	215,114	$	—	$	(17,730)	$	—	$	197,384
Government-sponsored commercial mortgage-backed securities	186,159		—		(12,765)		—		173,394
State and municipal bonds and obligations	83,851		1,784		(25)		—		85,610
Corporate bonds	29,000		1,070		—		—		30,070
	$	514,124	$	2,854	$	(30,520)	$	—	$	486,458


	As of December 31, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
	(In thousands)
Debt securities:
Government-sponsored residential mortgage-backed securities	$	231,709	$	—	$	(29,438)	$	—	$	202,271
Government-sponsored commercial mortgage-backed securities	189,006		—		(19,553)		—		169,453
	$	420,715	$	—	$	(48,991)	$	—	$	371,724

The Company did not record a provision for estimated credit losses on any HTM securities for either the three and nine months ended September 30, 2025 or 2024. The accrued interest receivable on HTM securities totaled $2.9 million and $0.9 million as of September 30, 2025 and December 31, 2024, respectively, and is included within other assets on the Consolidated Balance Sheets. The Company did not record any write-offs of accrued interest receivable on HTM securities during either the three and nine months ended September 30, 2025 or 2024. No HTM securities held by the Company were delinquent on contractual payments as of either September 30, 2025 or December 31, 2024, nor were any HTM securities placed on non-accrual status during the nine and twelve-month periods then ended.

Available for Sale and Held to Maturity Securities Contractual Maturity

The amortized cost and estimated fair value of AFS and HTM securities by contractual maturities as of September 30, 2025 and December 31, 2024 are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties.

The scheduled contractual maturities of AFS and HTM securities as of the dates indicated were as follows:


	As of September 30, 2025
	Due in one year or less				Due after one year to five years				Due after five to ten years				Due after ten years				Total
	Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(In thousands)
AFS securities
Government-sponsored residential mortgage-backed securities	$	21	$	21	$	14,018	$	13,793	$	10,845	$	10,256	$	2,731,986	$	2,494,233	$	2,756,870	$	2,518,303
Government-sponsored commercial mortgage-backed securities	—		—		611,261		612,720		49,331		44,354		496,104		405,977		1,156,696		1,063,051
U.S. Treasury securities	—		—		50,034		50,326		—		—		—		—		50,034		50,326
State and municipal bonds and obligations	6,917		6,871		33,416		33,021		51,882		51,039		99,526		88,020		191,741		178,951
Total available for sale securities	6,938		6,892		708,729		709,860		112,058		105,649		3,327,616		2,988,230		4,155,341		3,810,631
HTM securities
Government-sponsored residential mortgage-backed securities	—		—		—		—		—		—		215,114		197,384		215,114		197,384
Government-sponsored commercial mortgage-backed securities	—		—		131,030		123,856		55,129		49,538		—		—		186,159		173,394
State and municipal bond obligations	—		—		—		—		—		—		83,851		85,610		83,851		85,610
Corporate bonds	—		—		—		—		29,000		30,070		—		—		29,000		30,070
Total held to maturity securities	—		—		131,030		123,856		84,129		79,608		298,965		282,994		514,124		486,458
Total	$	6,938	$	6,892	$	839,759	$	833,716	$	196,187	$	185,257	$	3,626,581	$	3,271,224	$	4,669,465	$	4,297,089


	As of December 31, 2024
	Due in one year or less				Due after one year to five years				Due after five to ten years				Due after ten years				Total
	Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(In thousands)
AFS securities
Government-sponsored residential mortgage-backed securities	$	561	$	557	$	21,535	$	20,940	$	13,212	$	12,268	$	3,064,020	$	2,528,130	$	3,099,328	$	2,561,895
Government-sponsored commercial mortgage-backed securities	—		—		436,515		404,181		270,546		235,853		655,458		521,077		1,362,519		1,161,111
U.S. Agency bonds	—		—		19,608		17,672		—		—		—		—		19,608		17,672
U.S. Treasury securities	49,947		49,717		49,837		47,902		—		—		—		—		99,784		97,619
State and municipal bonds and obligations	5,368		5,319		33,497		32,284		51,326		48,743		107,214		96,955		197,405		183,301
Total available for sale securities	55,876		55,593		560,992		522,979		335,084		296,864		3,826,692		3,146,162		4,778,644		4,021,598
HTM securities
Government-sponsored residential mortgage-backed securities	—		—		—		—		—		—		231,709		202,271		231,709		202,271
Government-sponsored commercial mortgage-backed securities	—		—		133,168		121,471		55,838		47,982		—		—		189,006		169,453
Total held to maturity securities	—		—		133,168		121,471		55,838		47,982		231,709		202,271		420,715		371,724
Total	$	55,876	$	55,593	$	694,160	$	644,450	$	390,922	$	344,846	$	4,058,401	$	3,348,433	$	5,199,359	$	4,393,322

Securities Pledged as Collateral

As of September 30, 2025 and December 31, 2024, securities with a carrying value of $711.9 million and $687.9 million, respectively, were pledged to secure public deposits and for other purposes required by law. As of September 30, 2025 and December 31, 2024, deposits with associated pledged collateral included cash accounts from the Company’s wealth management division (“Cambridge Trust Wealth Management”) and municipal deposit accounts. As of September 30, 2025 and December 31, 2024, securities with a carrying value of $158.8 million and $1.0 billion, respectively, were pledged as collateral to the FHLBB.

As of September 30, 2025 and December 31, 2024, the Company pledged securities with a carrying value of $420.1 million and $794.8 million, respectively, to the Federal Reserve Discount Window (the “Discount Window”).