If your spouse has understated or underpaid joint tax liabilities, the IRS has now lifted the 2 year limit for you to bring your claim for innocent spouse relief. In response to taxpayer and legislative pressure to lift the limitations period, the IRS has positively responded.
There are 3 types of innocent spouse relief. There is classic/regular innocent spouse relief, separate liability election and equitable relief. This change deals with the third type (equitable relief). Essentially, the taxpayer argues that it would be unfair (inequitable) for the IRS to hold the innocent spouse responsible for for an understatement of tax on a joint return, caused solely by erroneous reporting by the other spouse. Note, the changes do not affect the other 2 types of innocent spouse relief (regular and separation of liability relief).
If an innocent spouse previously sought equitable relief from the IRS of a joint liability, she could not go back more than two years from the beginning of collection activity. Taxpayers and lawmakers argued that this itself is inequitable. If one spouse has concealed or erroneously reported income, it is highly likely that such spouse would also conceal the IRS' collection activity.
So, bowing to these equity pressures, the IRS has given in and officially lifted the 2 year requirement. More good news, the changes are retroactive. In other words, the 2 year ban is lifted on all new and pending requests for relief. If you were previously denied based on the limitation, you may also re-apply using Form 8857, so long as the collection statute of limitations against the IRS (typically 10 years) has not expired.