20. INCOME TAXES
Deferred income taxes are determined using the liability method for the temporary differences between the financial reporting basis and income tax basis of the Company’s assets and liabilities. Deferred income taxes are measured based on the tax rates expected to be in effect when the temporary differences are included in the Company’s tax return. Deferred tax assets and liabilities are recognized based on anticipated future tax consequences attributable to differences between financial statement carrying amounts of assets and liabilities and their respective tax bases.
Deferred tax assets increased by $3,340,000 and $3,672,000 for the years ended December 31, 2016 and 2015, respectively. These amounts were fully offset by a corresponding increase in the tax valuation allowance resulting in no net change in deferred tax assets, respectively, during these periods.
No liability for unrecognized tax benefits was required to be reported at December 31, 2016 and 2015. Based on the Company's evaluation, it has concluded that there are no significant uncertain tax positions requiring recognition in the Company's financial statements. The Company's evaluation was performed for the tax years ended 2012 through 2015, the only periods subject to examination. The Company believes that its income tax positions and deductions will be sustained on audit and does not anticipate that adjustments, if any, will result in a material change to its financial position. For the years ended December 31, 2016 and 2015, there were no penalties or interest related to the Company’s income tax returns.
Total deferred tax assets and valuation allowances are as follows at December 31:
| 2016 | 2015 | |||||||
| Current deferred tax asset - inventory reserve | $ | 195,000 | $ | 195,000 | ||||
| Non-Current Deferred Tax Assets: | ||||||||
| Stock-based compensation expense | 10,022,000 | 7,272,000 | ||||||
| Net operating loss carryforwards | 7,558,000 | 7,213,000 | ||||||
| Deferred compensation not paid within 2.5 months | 509,000 | 369,000 | ||||||
| Accrued liabilities not paid | 466,000 | 451,000 | ||||||
| Accrued interest on notes to related parties | 199,000 | 140,000 | ||||||
| Total long-term deferred tax assets | 18,784,000 | 15,445,000 | ||||||
| Total deferred tax assets | 18,979,000 | 15,639,000 | ||||||
| Less: valuation allowance | (18,979,000 | ) | (15,639,000 | ) | ||||
| Net deferred tax assets | $ | - | $ | - | ||||
The differences between income tax (benefit) provision in the financial statements and the income tax (benefit) provision computed at the U.S. Federal statutory rate of 34% at December 31 are as follows:
| 2016 | 2015 | |||||||
| Federal tax provision at the statutory rate | 34.0 | % | 34.0 | % | ||||
| State income tax benefit, net of federal benefit | (0.8 | ) | (0.9 | ) | ||||
| Stock-based compensation expense | (32.9 | ) | (29.7 | ) | ||||
| Deferred compensation not paid within 2.5 months | (1.7 | ) | 0.6 | |||||
| Accrued interest not deductible for tax return purposes | (1.7 | ) | (3.4 | ) | ||||
| Net change in net operating loss carryforwards | (4.5 | ) | (7.2 | ) | ||||
| Loss on conversion of convertible notes | (0.7 | ) | (1.1 | ) | ||||
| Decrease (increase) in estimated fair value of embedded derivative liabilities | 2.3 | (0.6 | ) | |||||
| Accrued liabilities not deductible for tax return purposes | (0.2 | ) | (0.1 | ) | ||||
| Total | (6.2 | ) | (8.4 | ) | ||||
| Valuation allowance | 6.2 | 8.4 | ||||||
| Effective tax rate | 0.0 | % | 0.0 | % | ||||
At December 31, 2016, the Company had available, $20,494,000 of net operating loss carryforwards which may be used to reduce future federal taxable income, expiring between 2018 and 2036. At December 31, 2016, the Company had available $10,154,000 of net operating loss carryforwards which may be used to reduce future state taxable income, expiring between 2029 and 2036.