Total nonperforming loans (nonaccrual and greater than 90 days late but still accruing) were $3.0 million, or 0.05%, of loans receivable at June 30, 2021, compared to $6.3 million, or 0.11%, of loans receivable at December 31, 2020 and $6.7 million, or 0.16%, at June 30, 2020.
As a percentage of nonperforming loans, the allowance for loan losses was 956.9% at June 30, 2021 compared to 435.1% at December 31, 2020 and 307.2% at June 30, 2020. The changes compared to both periods were primarily due to the changes in the nonperforming loans.
Total loans greater than 30 days past due were $3.3 million at June 30, 2021, $47.8 million at December 31, 2020, and $8.9 million at June 30, 2020.
Traditional Special Mention (Watch) loans were $149.0 million at June 30, 2021, compared to $152.9 million at December 31, 2020 and $46.4 million at June 30, 2020. The increase compared to June 30, 2020 reflected certain multi-family projects that have experienced cost over-runs funded by the borrower and lower than projected rent collections and occupancy levels, all of which have contributed to lower than projected cash flow of the projects. An additional category of Special Mention (Watch) loans was added as of June 30, 2020, and as of June 30, 2021 included $210,000 in arrangements related to COVID-19 deferral plans that were not already included in the traditional Special Mention or Substandard categories. Classified (substandard, doubtful and loss) loans were $7.4 million at June 30, 2021, $14.5 million at December 31, 2020 and $14.1 million at June 30, 2020.
During the three months ended June 30, 2021 there were $86,000 of charge-offs and $6,000 of recoveries, compared to $131,000 of charge-offs and no recoveries for the three months ended June 30, 2020.
For the six months ended June 30, 2021, there were $160,000 of charge-offs and $8,000 of recoveries, compared to $132,000 of charge-offs and $44,000 of recoveries for the six months ended June 30, 2020.
Comparison of Operating Results for the Three Months Ended June 30, 2021 and 2020
General. Net income for the three months ended June 30, 2021 was $51.4 million, an increase of $10.3 million, or 25%, from net income for the three months ended June 30, 2020. The increase was primarily due to a $13.2 million, or 26% increase in net interest income that reflected a 57% decrease in the cost of deposits and a 7% increase in interest income from higher loan balances as well as a $8.0 million, or 47%, increase in gain on sale of loans.
Partially offsetting the increases to net income was a $7.0 million, or 60%, increase in salaries and employee benefits to support higher loan production volumes and a $3.7 million increase in the provision for income taxes associated with the 25% increase in pre-tax income.
Net Interest Income. Net interest income increased $13.2 million, or 26%, to $64.4 million for the three months ended June 30, 2021, compared with the three months ended June 30, 2020. The 26% increase reflected a $8.7 million, or 57%, decrease in the cost of deposits and a $4.3 million, or 7%, increase in interest income from higher loan balances. The interest rate spread of 2.68% for the second quarter of 2021 increased 37 basis points compared to 2.31% in the second quarter of 2020.
Our net interest margin increased 33 basis points, to 2.75%, for the three months ended June 30, 2021 from 2.42% for the three months ended June 30, 2020. The increase in net interest margin reflected lower funding costs and higher loan balances that outpaced lower interest rates on loans.
Interest Income. Interest income increased $4.2 million, or 6%, to $72.4 million for the three months ended June 30, 2021, compared with the three months ended June 30, 2020. This increase was primarily attributable to significant multi-family loan growth that was partially offset by lower rates.