December31,
December31,
2019
2018
Deferred tax assets:
Net operating loss carry forwards
$46,273
$43,869
Research and development credits, net of uncertain tax positions
25,386
22,051
Accruals, reserves, and other
12,021
11,264
Stock-based compensation
3,306
2,628
Depreciation and amortization
2,219
1,952
Operating lease liability
7,061
—
Gross deferred tax assets
96,266
81,764
Valuation allowance
(85,743)
(78,681)
Total deferred tax assets
10,523
3,083
Deferred tax liabilities:
Deferred contract acquisition costs
(2,245)
(2,256)
Operating lease right of use asset
(7,088)
—
Other
(19)
(13)
Total deferred tax liabilities
(9,352)
(2,269)
Net deferred tax assets
$1,171
$814
the tax effects of temporary differences that give rise to significant portions of deferred tax assets -liabilities are as follows -in thousands : .
recognition of deferred tax assets is appropriate when realization of these assets is more likely than not .
based upon the weight of available evidence which includes our historical operating performance and the recorded cumulative net losses in prior fiscal periods we recorded a full valuation allowance of $ 85 .
7 million and $ 78 .
7 million against the u .
s .
net deferred tax assets as of december 31 2019 and 2018 respectively .
for the years ended december 31 2019 and 2018 the valuation allowance increased by $ 7 .
1 million and $ 6 .
2 million respectively .
as of december 31 2019 and 2018 we had u .
s .
federal net operating loss carryforwards of $ 193 .
8 million and $ 185 .
0 million respectively and state net operating loss carryforwards of $ 84 .
6 million and $ 75 .
3 million respectively .
the federal net operating loss carryforwards will expire at various dates beginning in the year ending december 31 2025 if not utilized .
the state net operating losses expire in various years ending between 2023 and 2039 if not utilized .
additionally as of december 31 2019 and 2018 we had u .
s .
federal research and development credit carryforwards of $ 15 .
3 million and $ 13 .
3 million and state research and development credit carryforwards of $ 16 .
4 million and $ 14 .
2 million respectively .
the federal credit carryforwards will begin to expire at various dates beginning in 2025 while the state credit carryforwards can be carried over indefinitely .
utilization of the net operating losses and credit carryforwards may be subject to an annual limitation provided for in the internal revenue code section 382 and similar state codes .
any annual limitation could result in the expiration of net operating loss and credit carryforwards before utilization .
with respect to our undistributed foreign subsidiaries ’ earnings we consider those earnings to be indefinitely reinvested and accordingly no related provision for u .
s .
federal and state income taxes has been provided .
our intention has not changed subsequent to the one-time transition tax under the tax act .
upon distribution of those earnings in the form of dividends or otherwise we may be subject to both u .
s .
income taxes subject to an adjustment for foreign tax credits and withholding taxes in the various countries .
as of december 31 2019 and 2018 the undistributed earnings approximated $ 13 .
6 million and $ 10 .
8 million respectively .
our undistributed earnings through december 31 2017 have been taxed under the one-time transition tax under the tax act .

Question: What is the company's valuation allowance in 2018?

Question: What is the company's valuation allowance in 2019?

Question: What is the 2019 net deferred tax assets?

Question: What is the increase in valuation allowance between 2018 and 2019?

Question: What is the total net deferred taxes between 2018 to 2019?

Question: What is the percentage change in research and development credits, net of uncertain tax positions between 2018 and 2019?