Held to maturity and available for sale investment securities have been classified according to management’s intent and were as follows as of March 31, 2021 and September 30, 2020 (dollars in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
March 31, 2021
Held to maturity
Mortgage-backed securities ("MBS"):
U.S. government agencies	$	21,888	$	1,164	$	(9)	$	23,043
Private label residential	5,056		312		(23)		5,345
U.S. Treasury and U.S. government agency securities	9,021		—		(68)		8,953
Bank issued trust preferred securities	500		—		(3)		497
Total	$	36,465	$	1,476	$	(103)	$	37,838

Available for sale

MBS: U.S. government agencies	$	69,001	$	282	$	(99)	$	69,184
Total	$	69,001	$	282	$	(99)	$	69,184

September 30, 2020
Held to maturity
MBS:
U.S. government agencies	$	27,161	$	1,635	$	(3)	$	28,793
Private label residential	229		307		(1)		535
Bank issued trust preferred securities	500		—		(1)		499
Total	$	27,890	$	1,942	$	(5)	$	29,827

Available for sale
MBS: U.S. government agencies	$	57,797	$	178	$	(68)	$	57,907

Total	$	57,797	$	178	$	(68)	$	57,907


	Less Than 12 Months					12 Months or Longer					Total
	Estimated Fair Value		Gross Unrealized Losses		Quantity	Estimated Fair Value		Gross Unrealized Losses		Quantity	Estimated Fair Value		Gross Unrealized Losses
Held to maturity
MBS:
U.S. government agencies	$	2,098	$	(8)	3	$	34	$	(1)	4	$	2,132	$	(9)
Private label residential	4,836		(23)		1	2		—		2	4,838		(23)
U.S. Treasury and U.S. government agency securities	8,953		(68)		3	—		—		—	8,953		(68)
Bank issued trust preferred securities	497		(3)		1	—		—		—	497		(3)
Total	$	16,384	$	(102)	8	$	36	$	(1)	6	$	16,420	$	(103)

Available for sale

MBS: U.S. government agencies	$	22,873	$	(99)	12	$	—	$	—	—	$	22,873	$	(99)
Total	$	22,873	$	(99)	12	$	—	$	—	—	$	22,873	$	(99)


	Less Than 12 Months					12 Months or Longer					Total
	Estimated Fair Value		Gross Unrealized Losses		Quantity	Estimated Fair Value		Gross Unrealized Losses		Quantity	Estimated Fair Value		Gross Unrealized Losses
Held to maturity
MBS:
U.S. government agencies	$	5,130	$	(2)	4	$	39	$	(1)	4	$	5,169	$	(3)
Private label residential	7		—		1	11		(1)		2	18		(1)
Bank issued trust preferred securities	499		(1)		1	—		—		—	499		(1)

Total	$	5,636	$	(3)	6	$	50	$	(2)	6	$	5,686	$	(5)

Available for sale
MBS:
U.S. government agencies	$	21,464	$	(68)	11	$	—	$	—	—	$	21,464	$	(68)

Total	$	21,464	$	(68)	11	$	—	$	—	—	$	21,464	$	(68)

The Company has evaluated the investment securities in the above tables and has determined that the declines in their fair value are temporary. The unrealized losses are primarily due to changes in market interest rates and spreads in the market for mortgage-related products. The fair value of these securities is expected to recover as the securities approach their maturity dates and/or as the pricing spreads narrow on mortgage-related securities. The Company has the ability and the intent to hold the investments until the fair value recovers. Furthermore, as of March 31, 2021, management does not have the intent to sell

any of the securities classified as available for sale where the estimated fair value is below the recorded value and believes that it is more likely than not that the Company will not have to sell such securities before a recovery of cost (or recorded value if previously written down).

The Company bifurcates OTTI into (1) amounts related to credit losses which are recognized through earnings and (2) amounts related to all other factors which are recognized as a component of other comprehensive income (loss). To determine the component of the gross OTTI related to credit losses, the Company compared the amortized cost basis of the OTTI security to the present value of its revised expected cash flows, discounted using its pre-impairment yield. The revised expected cash flow estimates for individual securities are based primarily on an analysis of default rates, prepayment speeds and third-party analytic reports. Significant judgment by management is required in this analysis that includes, but is not limited to, assumptions regarding the collectability of principal and interest, net of related expenses, on the underlying loans.

The following table presents a summary of the significant inputs utilized to measure management’s estimates of the credit loss component on OTTI securities as of March 31, 2021 and 2020:


	Range				Weighted
	Minimum		Maximum		Average
March 31, 2021
Constant prepayment rate	6.00	%	15.00	%	13.18	%
Collateral default rate	1.73	%	28.92	%	13.94	%
Loss severity rate	—	%	18.93	%	5.79	%

March 31, 2020
Constant prepayment rate	6.00	%	15.00	%	10.91	%
Collateral default rate	1.86	%	22.47	%	10.44	%
Loss severity rate	—	%	16.34	%	4.02	%



	Three Months Ended March 31, 2021		Three Months Ended March 31, 2020
	Held To Maturity		Held To Maturity
Total recoveries	$	3	$	3
Adjustment for portion of OTTI transferred from other comprehensive income (loss) before income taxes (1)	—		—
Net recoveries recognized in earnings (2)	$	3	$	3


	Six Months Ended March 31, 2021		Six Months Ended March 31, 2020
	Held To Maturity		Held To Maturity
Total recoveries	$	8	$	106
Adjustment for portion of OTTI transferred from other comprehensive income (loss) before income taxes (1)	—		—
Net recoveries recognized in earnings (2)	$	8	$	106

The following table presents a roll forward of the credit loss component of held to maturity and available for sale debt securities that have been written down for OTTI with the credit loss component recognized in earnings for the six months ended March 31, 2021 and 2020 (dollars in thousands):


	Six Months Ended March 31,
	2021		2020
Beginning balance of credit loss	$	885	$	1,071



Subtractions:
Realized losses previously recorded as credit losses	(5)		(60)
Recovery of prior credit loss	(8)		(106)
Ending balance of credit loss	$	872	$	905

During the six months ended March 31, 2021, the Company recorded a $5,000 net realized loss (as a result of investment securities being deemed worthless) on 13 held to maturity investment securities, all of which had been recognized previously as a credit loss. During the six months ended March 31, 2020, the Company recorded a $60,000 net realized loss (as a result of investment securities being deemed worthless) on 19 held to maturity investment securities, all of which had been recognized previously as a credit loss.

The recorded amount of investment securities pledged as collateral for public fund deposits, federal treasury tax and loan deposits, FHLB collateral and other non-profit organization deposits totaled $96.24 million and $81.03 million at March 31, 2021 and September 30, 2020, respectively.

The contractual maturities of debt securities at March 31, 2021 were as follows (dollars in thousands). Expected maturities may differ from scheduled maturities due to the prepayment of principal or call provisions.


	Held to Maturity				Available for Sale
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due within one year	$	—	$	—	$	1,428	$	1,421
Due after one year to five years	8,230		8,290		2,829		2,829
Due after five years to ten years	13,703		14,180		19,173		19,236
Due after ten years	14,532		15,368		45,571		45,698
Total	$	36,465	$	37,838	$	69,001	$	69,184