Interest Expense. Total interest expense increased $461,000, or 391.6%, to $578,000 for the three months ended March 31, 2024, from $118,000 for the three months ended March 31, 2023. Interest expense on deposits increased $328,000, or 296.3%, due primarily to an increase of 111 basis points in the average cost of deposits to 1.50% for the three months ended March 31, 2024, from 0.39% for the three months ended March 31, 2023, and an increase of $2.0 million, or 1.7%, in the average balance of interest-bearing deposits to $117.0 million for the three months ended March 31, 2024, from $115.0 million for the three months ended March 31, 2023.
Interest expense on borrowings increased $133,000, or 1,887%, for the three months ended March 31, 2024, compared to the three months ended March 31, 2023. The increase was due to a 385 basis point increase in the weighted-average rate, to 4.87% for the three months ended March 31, 2024, and an $8.8 million increase in the average balance outstanding, to $11.5 million for the three months ended March 31, 2024, from $2.7 million for the three months ended March 31, 2023.
Net Interest Income. Net interest income increased $55,000, or 4.1%, to $1.4 million for the three months ended March 31, 2024, compared to $1.3 million for the three months ended March 31, 2023. The increase reflected an increase in the net interest margin to 3.78% for the three months ended March 31, 2024, from 3.70% for the three months ended March 31, 2023, while the average net interest-earning assets decreased $8.0 million year to year. The net interest margin was impacted by a series of interest rate increases in the economy during 2023 and 2022.
Provision for Credit Losses. Based on an analysis of the factors described in “Critical Accounting Policies—Allowance for Credit Losses,” management determined that a provision for credit losses was not required for either of the three month periods ended March 31, 2024 and 2023. The allowance for credit losses was $967,000 at March 31, 2024 and $934,000 at September 30, 2023 and represented 0.70% of total loans at both March 31, 2024 and September 30, 2023. The increase in the allowance for credit losses was due to the adoption of ASU 2016-13 effective October 1, 2023, which resulted in an increase of $32,000 to the allowance. The determination over the adequacy of the allowance for credit losses was due primarily to the low balances of nonperforming loans, delinquent loans and no net charge-offs in both periods.
Total nonperforming loans were $674,000 at March 31, 2024, compared to $477,000 at September 30, 2023. Classified loans totaled $674,000 at March 31, 2024, compared to $477,000 at September 30, 2023, and total loans past due greater than 30 days were $1.5 million and $1.3 million at those respective dates. As a percentage of nonperforming loans, the allowance for credit losses was 127.1% at March 31, 2024 compared to 195.7% at September 30, 2023.
The allowance for credit losses reflects the estimate management believes to be appropriate to cover incurred probable losses which were inherent in the loan portfolio at March 31, 2024 and 2023. While management believes the estimates and assumptions used in the determination of the adequacy of the allowance are reasonable, such estimates and assumptions could be proven incorrect in the future, and the actual amount of future provisions may exceed the amount of past provisions, and the increase in future provisions that may be required may adversely impact the Bank’s financial condition and results of operations. In addition, bank regulatory agencies periodically review the allowance for credit losses and may require an increase in the provision for credit losses or the recognition of loan charge-offs, based on judgments different than those of management.
Non-Interest Income. Non-interest income totaled $153,000 for the three months ended March 31, 2024, an increase of $3,000, or 2.3%, from the three months ended March 31, 2023. The increase was due primarily to an $11,000, or 47.2%, increase in late charges and fees on loans and a $6,000 gain on sale of foreclosed assets, which were partially offset by an $8,000 decrease in gains on sales of loans and a $6,000, or 34.8%, decrease in loan servicing fees.
Noninterest Expense. Noninterest expense increased $284,000, or 26.2%, to $1.4 million for the three months ended March 31, 2024, compared to $1.1 million for the three months ended March 31, 2023. The increase was due primarily to a $91,000, or 17.0%, increase in salaries and employee benefits, a $59,000, or 116.0%, increase in professional services, a $35,000, or 189.4%, increase in loan expenses and a $24,000, or 28.7%, increase in other expense.