Please see answers to your questions below:
1. "I had approximately $20K basis and the liquidating distribution was approximately $30K, so it would appear I should report the $10K gain, presumably as a long-term capital gain?"
It depends. If these assets were held for longer than one year, yes, the liquidation would be reported as a long-term capital gain.
2. Additionally, future distributions would be handled as gains as there will be no basis left, is this correct?
Yes
3. At this point, I would surmise that I will have to amend my return to report this $10K capital gain, is this correct?
Yes, you will need to amend the return. Click the link for details: How do I amend my return? The amendment will affect any state filing, as well.
4. Or, could I wait until the final liquidation distributions are made and report the entire gain at that point in time?
It depends. The transactions must be reported on a cash basis when the assets are actually sold.
Please see TurboTax Employee Tax Expert ThomasM125's answer to this Community question: Handle liquidation distribution
@Jimmytax
