IRS audited a previously filed joint return, after date of separation, and assessed back taxes, penalties and interest owing for unreported income from my spouse. IRS granted me Innocent Spouse Relief and relieved me of the obligation to pay. My spouse claims I am responsible since the obligation was listed in our separation agreement. However, the obligation was zero at the time of separation. Two years after we signed the agreement, the debt was assessed and incurred.

To reiterate, note the agreement was a separation agreement and not a settlement agreement.

Who is responsible for this debt? Is it separate property since the debt was incurred after signing? Will the California Family Court honor the IRS determination of Innocent Spouse Relief and consider it separate property and liable to my spouse? Am I breaching the contract?

Also, I am having difficulty identifying applicable laws and/or previous cases and how my case applies to those laws.

Any advice will be much appreciated!