Section 179 expense deduction disallowed keeps changing, and I can't find the error. Can someone walk me through it?

[Mike9241]

it would change if business changes becuase its limited to business income. ir would also change if the tax basis of the 179 assey changed. 

[MaxA1]

Sec 179 deduction cannot exceed your net taxable business income for the year, and special limits apply to vehicles.  So if you're business income keeps changing due to income and/or expenses that you are adding on your return, this may be the reason why your disallowed amount keeps changing.