At September 30, 2019 and December 31, 2018, respectively, we had no material unrecognized tax benefits or accrued interest and penalties. Tax years 2016 through 2018 remained open for examination at September 30, 2019. We provide a valuation allowance when we believe it is more likely than not that we will not realize some portion of our tax assets. We established a valuation allowance of $264,467 related to a portion of the net operating loss carryforward of Le Mars at January 1, 2004 and a valuation allowance of $8.1 million for our net state operating loss carryforward. We have determined that we are not required to establish a valuation allowance for our other deferred tax assets of $25.2 million and $32.4 million at September 30, 2019 and December 31, 2018, respectively, because it is more likely than not that we will realize these deferred tax assets through reversals of existing temporary differences, future taxable income and the implementation of tax planning strategies.

Our deferred tax assets include a net operating loss carryforward of $1.2 million related to Le Mars, which will begin to expire in 2020 if not previously utilized. This carryforward is subject to an annual limitation of approximately $376,000.