8. Income Taxes

We had federal and state net operating loss ("NOL") carryforwards available of $97,166 and $34,813 at December 31, 2023, respectively. The federal NOL carryforwards can be carried forward indefinitely while $28,685 of the state NOL carryforwards have indefinite lives and the remaining amounts will expire between 2030 and 2043. We had federal interest expense carryforwards of $90,094 at December 31, 2023, which can be carried forward indefinitely. We also had state interest expense carryforwards in 13 states where the amounts vary by jurisdiction, which also have indefinite lives. We had federal general business credits of $3,539 at December 31, 2023, which can be carried forward for 20 years and if unused, will expire between 2037 and 2043.

As noted above, we had deferred tax assets related to both federal and state NOL and interest expense carryforwards. When determining the need for a valuation allowance, we consider all available positive and negative evidence, including taxable income in prior carryback years (if carryback is permitted under the relevant tax law), the timing of the reversal of existing taxable temporary differences, tax planning strategies and projected future taxable income. We adjust the valuation allowance in the period management determines it is more likely than not that we will not realize some or all of the deferred tax assets.

For financial reporting purposes, we established valuation allowances of $286 and $566 at December 31, 2023 and 2022, respectively, to offset deferred tax assets. The current and prior year valuation allowance relates to state attributes and carryovers.

Past ownership changes and other equity transactions may have triggered Sections 382 and 383 of the Internal Revenue Code, resulting in certain annual limitations on the utilization of existing federal and state net operating losses and credits. Such provisions may limit the potential future tax benefit to be realized by us from its accumulated net operating losses and tax credit carryforwards.

On August 9, 2022, the Creating Helpful Incentives to Produce Semiconductors (“CHIPS”) Act of 2022 was signed into law. The CHIPS Act is designed to boost domestic semiconductor manufacturing and encourage US research activities. Later that month, on August 16, 2022, the Inflation Reduction Act (“IRA”) of 2022 was signed into law. The IRA creates a new book-minimum tax on certain large corporations and an excise tax on stock buybacks while also providing incentives to address climate change mitigation and clean energy, among other items. Most of these changes became effective for the 2023 tax year and after initial evaluation, we do not currently expect these laws to have a material effect on the consolidated financial statements.

The income tax expense recorded in 2023 is different from the expected statutory federal and state tax benefit primarily due to a $2,115 income tax benefit related to equity award exercises and/or vesting in 2023, which is net of the impact of the internal revenue code rules and regulations related to the deductibility of executive compensation by publicly held companies.

We file income tax returns in the U.S. federal and various state tax jurisdictions and are subject to varying statutes of limitation in each jurisdiction. As of December 31, 2023, we are not under audit for federal or state income tax purposes. In general, our federal tax return may be subject to examination for the 2020 through 2022 tax years, while for state purposes, the 2019 through 2022 years are generally open to examination, with some states having either a three- or four-year statute of limitations. Our usage of NOL carryovers also permits taxing authorities to adjust aspects of tax returns that may be outside of these statutes of limitation.

Our policy is to recognize interest and penalties related to income tax matters in income tax (benefit) provision. We accrued interest and penalties of $175 as of December 31, 2023 in income tax expense. We neither accrued for nor recognized any interest or penalties in income tax expense as of December 31, 2022 or 2021. We have not accrued for any uncertain tax positions as of December 31, 2023 or 2022 and we believe that it is unlikely that there will be a significant increase or decrease of any unrecognized tax benefits within the next twelve months.