The following tables present the Company’s loans (UPB) collateralized by real estate as of December 31, 2022 and 2021 (in thousands).


December 31, 2022
Description	Interest Rate	Final Maturity Date	Unpaid Principal Balance (1) (2)		Nonaccrual Unpaid Principal Balance
1-4 unit residential (3)
Under $1.0 million	4.0% - 13.5%	January 1, 2053	$	1,374,726	$	127,125
$1.0 million and over	4.0% - 11.5%	January 1, 2053		476,813		57,508
				1,851,539		184,633
Traditional commercial (4)
Under $1.0 million	4.0% - 13.7%	January 1, 2053		1,196,378		69,763
$1.0 million and over	4.0% - 11.7%	January 1, 2053		464,569		38,393
				1,660,947		108,156
Total at December 31, 2022			$	3,512,486	$	292,789


December 31, 2021
Description	Interest Rate	Final Maturity Date	Unpaid Principal Balance (1) (2)		Nonaccrual Unpaid Principal Balance
1-4 unit residential (3)
Under $1.0 million	4.0% - 13.5%	January 1, 2052	$	987,069	$	127,214
$1.0 million and over	4.0% - 11.5%	January 1, 2052		325,025		44,426
				1,312,094		171,640
Traditional commercial (4)
Under $1.0 million	3.1% - 13.0%	January 1, 2052		969,599		73,039
$1.0 million and over	4.0% - 10.2%	January 1, 2052		305,528		28,421
				1,275,127		101,460
Total at December 31, 2021			$	2,587,221	$	273,100

(1)

The aggregate cost of the Company’s loan portfolio for Federal income tax purposes was $3,553,379 and $2,621,093 as of December 31, 2022 and 2021, respectively.

(2)

As of December 31, 2022 and 2021, $168.4 million and $155.1 million, respectively, of the total UPB were interest-only loans with interest payable monthly and the principal payable at maturity.

(3)

The principal and interest on the 1-4 unit residential mortgage loans is payable monthly over the life of the loan to maturity. These loans generally contain a 3% prepayment penalty provision if the loan is prepaid within the first 3 years.

(4)

The principal and interest on the traditional commercial mortgage loans is payable monthly over the life of the loan to maturity. These loans generally contain a 5% prepayment penalty provision if the loan is prepaid within the first 3 years.

The following table presents the reconciliation of the UPB of mortgage loans for the years ended December 31, 2022, 2021, and 2020:


	December 31,
	2022			2021			2020
Balance at beginning of period	$	2,587,220		$	1,944,804		$	2,059,344
Addition during period:
New mortgage loans		1,761,853			1,326,275			435,037
Acquisition		17,657			22,437			4,643
Capitalized Interest		1,604			2,045			7,814
Deduction during period:
Collection of principal		(525,986	)		(568,081	)		(374,576	)
Collection of capitalized interest		(2,155	)		(2,163	)		—
Foreclosures		(10,031	)		(11,603	)		(10,781	)
Mortgages sold		(317,676	)		(126,494	)		(176,677	)
Balance at end of period	$	3,512,486		$	2,587,220		$	1,944,804