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 benefit of 2% for the three months ended March 31, 2020 and 6% for the six months ended March 31, 2020.

The current quarter rate was impacted by nondeductible goodwill impairment of $527 million of the $530 million charge taken during the quarter. The current six months tax rate was impacted by the nondeductible goodwill impairment and favorable tax discrete item from the tax benefit related to the Swiss Tax Reform.

The overall effective tax rate was 2% for the three months ended March 31, 2019 and a negative 2500% for the six months ended March 31, 2019. The quarter tax rate was primarily impacted by certain nondeductible restructuring costs, as well as $11 million in favorable tax discrete items including nontaxable earnings in deferred compensation related investments and other items. The six month period was primarily impacted by the items referenced in the three-month period, as well as a net $30 million from unfavorable tax discrete items including the final assessment of the Tax Act and other items.

Changes in unrecognized tax benefits are summarized as follows for the six months ended March 31, 2020.

(In millions)
Balance at October 1, 2019	$	165
Increases related to positions taken on items from prior years		2
Decreases related to positions taken on items from prior years		(1	)
Increases related to positions taken in the current year		3
Lapse of statute of limitations		(2	)
Balance at March 31, 2020	$	167

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 $1 million and $3 million for continuing operations. 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.