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The basics
An itemized deduction is not a refund and it is not another bill. It is an allowed amount that reduces the income a tax ladder reads. The federal return and a state return can each make their own choice between a standard deduction and an itemized total, so the two figures can legitimately differ and should never be added together.
Read the annual ledger
What each deduction row means
Federal itemized deductions
The allowed Schedule A total used by the federal return when it beats the federal standard deduction. MoneyWhatIf shows the itemized figure only in years when that choice wins.
State, local & property tax
Eligible state and local income or sales tax plus personal property tax, after the federal SALT ceiling and its income-based reduction. The tooltip can therefore say ‘of $X paid’: the larger number is the cash paid, while the row is the amount allowed into Schedule A.
Mortgage interest
The personal-use share of modeled mortgage interest after the acquisition-debt ceiling. Interest assigned to a rental is handled with that property’s rental-income calculation instead of being counted here again.
Charitable giving
Declared giving eligible for Schedule A after qualified charitable distributions are removed and the modeled income-based floor and ceiling are applied. A QCD lowers IRA income instead, so the same gift cannot also be itemized.
Medical expenses
The allowed part of declared eligible medical spending above the modeled adjusted-gross-income floor. The row is the amount over the floor, not the household’s total medical cash spending.
High-income limit
A reduction to otherwise allowed itemized deductions at high income. The annual ledger prints it with a plus sign because it gives part of the deduction back, reconciling the component lines to the smaller allowed total.
State itemized deductions
A separate candidate compared with that state’s own standard deduction; the state calculation uses the larger amount. For California, the modeled Schedule CA total excludes state and local income tax and California SDI, lets personal property tax escape the federal SALT ceiling, and then applies California’s high-income reduction. It is not added to the federal itemized amount.
Illustrative numbers
Why California can show a different total
California income tax paid$18,000
Personal property tax$12,000
Modeled mortgage interest$20,000
Charitable giving$2,000
Before any income-based reduction, the federal taxes line can include the income tax and property tax subject to its SALT ceiling. California removes the $18,000 California income tax from its own deduction but allows the $12,000 property-tax line without the federal SALT ceiling. That different starting point is why the two itemized totals need not match.
Calculation transparency
How it works in MoneyWhatIf
- 01
The federal calculation builds Schedule A from modeled state and local income tax, the personal share of property tax, allowed mortgage interest, declared charitable giving, and declared medical costs. It applies each category’s floor or ceiling and the modeled high-income reduction before comparing the total with the federal standard deduction.
- 02
Only a federal itemized total that beats the standard deduction is published on the projection row. The breakdown is carried beside that row for the Deductions ledger and graph; it is explanatory tax data, not money in or money out.
- 03
A supported state builds its own itemized figure from the components its rules allow, applies its own cap and high-income treatment, and compares that result with the state standard deduction inside the state tax calculation.
- 04
For California, the model excludes state and local income tax and SDI from the state taxes line, leaves personal property tax uncapped, and applies California’s six-percent high-income reduction above the modeled filing-status threshold.
- 05
Today’s-money mode discounts the total and every disclosed component by the same year-specific factor, so the detailed rows still reconcile to the graph bar.
Keep in mind
Model limits
The model covers the deduction categories it collects: personal property tax, mortgage interest, charitable giving, and medical expenses. It does not reproduce every Schedule A or Schedule CA line, election, carryforward, miscellaneous deduction, casualty loss, or investment-interest worksheet.
California can allow home-acquisition interest beyond the current federal $750,000 debt ceiling in some cases. The projection currently carries its federally capped personal mortgage-interest amount into the California calculation, so that difference is not modeled.
Charitable and medical eligibility depends on facts the plan does not collect. Entered amounts are planning assumptions, not validation that a payment qualifies on a filed return.
Tax law and published thresholds change. This page documents the rule snapshot encoded by the model, not a promise about a future return.
This explanation documents the planning model. It is educational, not individualized tax, legal, Medicare, or investment advice.
Where it appears
Where to use it
See this concept in context, with a guide to each page and its controls.
The words behind it
Related financial terms
Plain-English definitions, with 2026 figures and worked examples, from the financial terms glossary.