General and Administrative
For the three months ended September 30, 2022, general and administrative expense increased $0.6 million, or 27.9 percent, to $2.9 million from $2.3 million for the same period last year. This increase is primarily due to higher legal and professional expenses and increased payroll and benefit expenses.
For the nine months ended September 30, 2022, general and administrative expense increased $0.8 million, or 10.4 percent, to $8.0 million from $7.2 million for the same period last year. This increase is primarily due to higher legal and professional expenses and increased payroll and benefit expenses.
Sales and Marketing
For the three months ended September 30, 2022, sales and marketing expense increased $0.4 million, or 17.5 percent, to $3.0 million from $2.6 million for the same period last year. This increase is primarily due to higher sales commissions, sales activities expenses, and payroll and benefits expenses.
For the nine months ended September 30, 2022, sales and marketing expense increased $1.6 million, 21.3 percent, to $9.0 million from $7.4 million for the same period last year. This increase is primarily due to higher sales commissions, sales activities expenses, and payroll and benefits expenses.
Research and Development
For the three months ended September 30, 2022, and 2021, research and development expense increased remained constant at $0.5 million. This is primarily due to higher consulting expenses related to next generation pump, payroll and benefits expenses offset by reduction in prototype expense.
For the nine months ended September 30, 2022, research and development expense increased $0.3 million, or 18.7 percent, to $1.7 million from $1.4 million for the same period last year. This is primarily due to higher payroll and benefits expenses as well as prototype and consulting expenses related to next generation pump.
Other Income, Net
Other income, net consists of interest income, foreign currency gains and losses, and other miscellaneous income. For the three months ended September 30, 2022, other income net increased $0.1 million, or 1,372.5 percent to $0.1 million from $0.0 for the same period last year. This increase is due to interest received on income tax refunds and investment interest income.
Income Taxes
For the three and nine months ended September 30, 2022, we recorded a provision for income tax expense of $810,375 and $2,322,301, respectively. Our effective tax rate was 19.1 percent and 20.2 percent respectively and differed from the U.S. Federal statutory rate primarily due to U.S. state income tax expense, partially offset by benefits from foreign derived intangible income and research and development tax credits.
For the three and nine months ended September 30, 2021, we recorded a provision for income tax expense of $517,767 and $1,289,988, respectively. Our effective tax rate was 16.7 percent and 19.2 percent respectively and differed from the U.S. Federal statutory rate primarily due to U.S. state income tax expense, partially offset by benefits from foreign derived intangible income and research and development tax credits.
As of September 30, 2022, and December 31, 2021, we had not identified or accrued for any uncertain tax positions. We are currently unaware of any uncertain tax positions that could result in significant payments, accruals or other material deviations in this estimate over the next 12 months. We believe that our tax positions comply in all material respects with applicable tax law. However, tax law is subject to interpretation, and interpretations by taxing authorities could be different from ours, which could result in the imposition of additional taxes and penalties.
We file tax returns in the United States Federal jurisdiction and many U.S. state jurisdictions. Our returns are not currently under examination by the Internal Revenue Service. The Company remains subject to income tax examinations for our United States Federal and certain U.S. state income taxes for 2019 and subsequent years.