I have been using the Libra Tax site to manage my mining calculations for IRS tax purposes. You can link it to Coinbase or any other wallets you use.
The “Tax Report" will fulfill your reporting requirements for IRS Form 8949 and Schedule D.
http://www.libra.tech/I've used them 2 years now.
That being said, I'm expecting a refund for 2015 year and it's still 'processing'. I'm half expecting an audit.