The Tax Cuts and Jobs Act (Tax Act) was enacted on December 22, 2017. The Tax Act reduces the U.S. federal corporate tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and creates new taxes on certain foreign sourced earnings. Through September 30, 2018 we recorded provisional amounts for certain enactment date effects of the Tax Act by applying the guidance in SAB 118 because we had not yet completed our enactment date accounting for these effects. During the current quarter, Ashland completed its internal accounting assessment for the tax effects of enactment of the Tax Act and recorded adjustments to provisional amounts previously recorded. Ashland’s final assessment resulted in net unfavorable tax adjustments of $24 million during the three months ended December 31, 2018 primarily related to the one-time transition tax assessed on foreign cash and unremitted earnings. There could be additional guidance issued subsequent to December 31, 2018 that could impact our interpretation of the Tax Act and such changes could affect the amounts recorded.

Ashland remeasured certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, which is 21%. Ashland finalized its assessment of the provisional amount previously recorded for the remeasurement of the deferred tax balance which resulted in an unfavorable tax adjustment of $2 million during the three months ended December 31, 2018.

The one-time transition tax is based on Ashland's total post-1986 earnings and profits of foreign subsidiaries that were previously deferred from U.S. income taxes. Ashland finalized its assessment of the provisional amount previously recorded for this one-time transition tax liability which resulted in an unfavorable tax adjustment of $22 million during the three months ended December 31, 2018. After this final adjustment, the obligation for the one-time transition tax was $51 million as of December 31, 2018. No additional income taxes have been provided for any remaining undistributed foreign earnings not subject to the transition tax, or any additional outside basis difference inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations. Ashland determined that the amount of unrecognized deferred tax liability related to any remaining undistributed foreign earnings not subject to the transition tax and additional outside basis difference in these entities (i.e., basis difference in excess of that subject to the one-time transition tax) is not practicable at this time.

Regarding new Global Intangible Low-Taxed Income (GILTI) tax rules, Ashland made an election to treat taxes due on future GILTI exclusions as a current period expense when incurred.

Ashland’s effective tax rate in any interim period is subject to adjustments related to discrete items and the mix of domestic and foreign operating results. The overall effective tax rate was a negative rate of 51% for the three months ended December 31, 2018. The current quarter tax rate was impacted by income mix, certain nondeductible restructuring costs, as well as $30 million from unfavorable tax discrete items including the final assessment of the Tax Act referenced above and other items.

The overall effective tax rate was negative 45% for the three months ended December 31, 2017 and was primarily impacted by income mix and net unfavorable tax discrete adjustments of $16 million related to the Tax Act.

Changes in unrecognized tax benefits are summarized as follows for the three months ended December 31, 2018.

(In millions)
Balance at October 1, 2018	$	164
Decreases related to positions taken on items from prior years		(1	)
Increases related to positions taken in the current year		1
Lapse of statute of limitations		(1	)
Balance at December 31, 2018	$	163

From a combination of statute expirations and audit settlements in the next twelve months, Ashland expects a decrease in the amount accrued for uncertain tax positions of between $0 million and $2 million for continuing operation. It is reasonably possible that there could be other material changes to the amount of uncertain tax positions due to activities of the taxing authorities, settlement of audit issues or the reassessment of existing uncertain tax positions; however, Ashland is not able to estimate the impact of these items at this time.