Example 1. Computation of net unrealized built-in gain. (i)(A) X, a calendar year C corporation using the cash method, elects to become an S corporation on January 1, 1996. On December 31, 1995, X has assets and liabilities as follows: (B) Further, X must include a total of $60,000 in taxable income in 1996, 1997, and 1998 under section 481(a).

(ii) If, on December 31, 1995, X sold all its assets to a third party that assumed all its liabilities, X's amount realized would be $1,050,000 ($750,000 cash received + $300,000 liabilities assumed = $1,050,000). Thus, X's net unrealized built-in gain is determined as follows:

Example 2. Adjustment to net unrealized built-in gain for built-in gain in eliminated C corporation stock. (i) X, a calendar year C corporation, elects to become an S corporation effective January 1, 2005. On that date, X's assets (the first pool of assets) have a net unrealized built-in gain of $15,000. Among the assets in the first pool of assets is all of the outstanding stock of Y, a C corporation, with a fair market value of $33,000 and an adjusted basis of $18,000. On March 1, 2009, X sells an asset that it owned on January 1, 2005, and as a result has $10,000 of recognized built-in gain. X has had no other recognized built-in gain or built-in loss. X's taxable income limitation for 2009 is $50,000. Effective June 1, 2009, X elects under section 1361 to treat Y as a qualified subchapter S subsidiary (QSub). The election is treated as a transfer of Y's assets to X in a liquidation to which sections 332 and 337(a) apply.

(ii) Under paragraph (b) of this section, the net unrealized built in-gain of the first pool of assets is adjusted to account for the elimination of the Y stock in the liquidation. The net unrealized built-in gain of the first pool of assets, therefore, is decreased by $15,000, the amount by which the fair market value of the Y stock exceeded its adjusted basis as of January 1, 2005. Accordingly, for taxable years ending after June 1, 2009, the net unrealized built-in gain of the first pool of assets is $0.

(iii) Under §1.1374-2(a), X's net recognized built-in gain for any taxable year equals the least of X's pre-limitation amount, taxable income limitation, and net unrealized built-in gain limitation. In 2009, X's pre-limitation amount is $10,000, X's taxable income limitation is $50,000, and X's net unrealized built-in gain limitation is $0. Because the net unrealized built-in gain of the first pool of assets has been adjusted to $0, despite the $10,000 of recognized built-in gain in 2009, X has $0 net recognized built-in gain for the taxable year ending on December 31, 2009.

Example 3. Adjustment to net unrealized built-in gain for built-in loss in eliminated C corporation stock. (i) X, a calendar year C corporation, elects to become an S corporation effective January 1, 2005. On that date, X's assets (the first pool of assets) have a net unrealized built-in gain of negative $5,000. Among the assets in the first pool of assets is 10 percent of the outstanding stock of Y, a C corporation, with a fair market value of $18,000 and an adjusted basis of $33,000. On March 1, 2009, X sells an asset that it owned on January 1, 2005, resulting in $8,000 of recognized built-in gain. X has had no other recognized built-in gains or built-in losses. X's taxable income limitation for 2009 is $50,000. On June 1, 2009, Y transfers its assets to X in a reorganization under section 368(a)(1)(C).

(ii) Under paragraph (b) of this section, the net unrealized built in-gain of the first pool of assets is adjusted to account for the elimination of the Y stock in the reorganization. The net unrealized built-in gain of the first pool of assets, therefore, is increased by $15,000, the amount by which the adjusted basis of the Y stock exceeded its fair market value as of January 1, 2005. Accordingly, for taxable years ending after June 1, 2009, the net unrealized built-in gain of the first pool of assets is $10,000.

(iii) Under §1.1374-2(a), X's net recognized built-in gain for any taxable year equals the least of X's pre-limitation amount, taxable income limitation, and net unrealized built-in gain limitation. In 2009, X's pre-limitation amount is $8,000 and X's taxable income limitation is $50,000. The net unrealized built-in gain of the first pool of assets has been adjusted to $10,000, so X's net unrealized built-in gain limitation is $10,000. X, therefore, has $8,000 net recognized built-in gain for the taxable year ending on December 31, 2009. X's net unrealized built-in gain limitation for 2010 is $2,000.

Example 4. Adjustment to net unrealized built-in gain in case of prior gain recognition. (i) X, a calendar year C corporation, elects to become an S corporation effective January 1, 2005. On that date, X's assets (the first pool of assets) have a net unrealized built-in gain of $30,000. Among the assets in the first pool of assets is all of the outstanding stock of Y, a C corporation, with a fair market value of $45,000 and an adjusted basis of $10,000. Y has no current or accumulated earnings and profits. On April 1, 2007, Y distributes $18,000 to X, $8,000 of which is treated as gain to X from the sale or exchange of property under section 301(c)(3). That $8,000 is recognized built-in gain to X under section 1374(d)(3), and results in $8,000 of net recognized built-in gain to X for 2007. X's net unrealized built-in gain limitation for 2008 is $22,000. On June 1, 2009, Y transfers its assets to X in a liquidation to which sections 332 and 337(a) apply.

(ii) Under paragraph (b) of this section, the net unrealized built in-gain of the first pool of assets is adjusted to account for the elimination of the Y stock in the liquidation. The net unrealized built-in gain of that pool of assets, however, can only be adjusted to reflect the amount of built-in gain that was inherent in the Y stock on January 1, 2005 that has not resulted in recognized built-in gain during the recognition period. In this case, therefore, the net unrealized built-in gain of the first pool of assets cannot be reduced by more than $27,000 ($35,000, the amount by which the fair market value of the Y stock exceeded its adjusted basis as of January 1, 2005, minus $8,000, the recognized built-in gain with respect to the stock during the recognition period). Accordingly, for taxable years ending after June 1, 2009, the net unrealized built-in gain of the first pool of assets is $3,000. The net unrealized built-in gain limitation for 2009 is $0.