I think I just didn’t chose my words correctly. I just meant that the choice to file individually rather than jointly might have additional consequences on how much tax you pay. The consequences may not be $4K worth of additional tax (equal to the credit your wife might be entitled to), but you might want to speak with someone (an accountant) in order to determine what they would be.
Also, you may know that a married person filing individually only gets $4K, but that is what I was referring to. Here is the excerpt from the statute stating that.
IRC 36(b)(1)(B)
(B) Married individuals filing separately.–In the case of a married individual filing a separate return, subparagraph (A) shall be applied by substituting “$4,000” for “$8,000”.
