You must be talking about an S-Corp return where the company has been around for a while.

See the instructions, starting page 37:

http://www.irs.gov/pub/irs-pdf/i1120s.pdf

"The shareholders' undistributed taxable income previously taxed account, also called previously taxed income (PTI), is maintained only if the corporation had a balance in this account at the start of its 2009 Tax Year (page 38)."

A distribution should have been made under Section 1375(d), assuming the Corp is continuing its existence, before this amount should change.

"A distribution from the PTI account is tax free to the extent of a shareholder's basis in his or her stock in the corporation."

Thank you for your question.

The account should only decrease.

It doesn't sound like your return is being prepared correctly.

I'll show you the 2008 instructions now:

http://www.irs.ustreas.gov/pub/irs-prior/i1120s--2008.pdf

"The shareholders' undistributed taxable income previously taxed account, also called previously taxed income (PTI), is maintained only if the corporation had a balance in this account at the start of its 2008 tax year. If there is a beginning balance for the 2008 tax year, no adjustments are made to the account except to reduce the account for distributions made under section 1375(d) (as in effect before the enactment of the Subchapter S Revision Act of 1982)... (page 37)."

Hmmm....?

It is possible to have distributed all of your PTI balance in 2008, in which case you wouldn't have a 2009 beginning balance, but without looking at your return, I would not know. This equity that you do want to account for correctly so that you don't end up paying too much in tax on distributions or upon the eventual sale of your company, etc.