Credits and Deduction Phaseouts - What is the base number?

[Pants]

So, trying to figure out what base number the IRS uses for their base when they are calculating where deducitons phase out. I know it would exclude 401k and other tax-free accounts, but does the number include the amount you pay into SS, Medicare, Income tax, etc?

I don't know if that makes sense. So, trying again:

Child tax credit begins to phase out at 110k. Is that 110k Gross income - deposits to tax-free accounts? Or is it Gross income - deposits to tax-free accounts - taxes paid?

[braje]

I believe the phase out are based on you AGI.  SS, Medicare and income tax withheld would have no effect on your AGI. Braje

[Rocky Mtn Saver]

AGI is listed as a line on your 1040, so you should be able to see what it includes and what it doesn't. 

[taxref]

Phase outs for various deductions and credits are usually based on MAGI (modified adjusted gross income).  MAGI is different than both gross income and AGI.  To determine ones MAGI, one starts with AGI, but then adds back certain items.

The trick is, there is no standard formula for MAGI.  Rather, MAGI is computed differently for each deduction or credit.  For example, MAGI for the child tax credit may well be computed differently than MAGI for an education credit.

For purposes of the 2013 child tax credit, MAGI is described on Page 3 of Publication 972.

[DVM gone riding]

Great yet another credit I won't get assuming I get married before having children   I really think politicians need to rethink these limits 110k just is NOT that much money and don't we want to encourage two income stable families to have kids