We file a consolidated federal income tax return for all of our wholly-owned subsidiaries, including Sirius XM.  Income tax expense for the three months ended September 30, 2015 and 2014 was $112,543 and $89,044, respectively, and $296,893 and $252,614, respectively, for the nine months ended September 30, 2015 and 2014.  We estimate that our annual effective tax rate for the year ending December 31, 2015 will be 37.9%. Our effective tax rate for the three and nine months ended September 30, 2015 was 40.3% and 44.2%, respectively.  Our effective tax rate for the nine months ended September 30, 2015 was impacted by tax law changes in the District of Columbia and New York City.  The tax law change in the District of Columbia will reduce our future taxes and thus we will use less of certain net operating losses in the future which resulted in a $44,392 increase in our valuation allowance during the nine months ended September 30, 2015.  The tax law change in New York City will increase certain net operating losses to be utilized in the future resulting in a $14,831 increase in our deferred tax asset during the nine months ended September 30, 2015.  Our effective tax rate for the nine months ended September 30, 2014 was 41.9% due to the impact of the loss on change in fair value of the derivative related to the share repurchase agreement with Liberty Media.

As of September 30, 2015 and December 31, 2014, we had a valuation allowance related to deferred tax assets of $49,849 and $4,995, respectively, that were not likely to be realized due to certain state net operating loss limitations and acquired net operating losses that we were not likely to utilize.