Finance Maxxing
Income Tax Basics
Filing Status
Determines your bracket thresholds and standard deduction.
Your filing status affects nearly every tax calculation — brackets, deduction amounts, credit eligibility, and phase-out thresholds.
Filing Status Comparison (2025)
| Status | Standard Deduction | 22% Bracket Starts | Notes |
|---|---|---|---|
| Single | ~$15,000 | $48,476 | Default for unmarried |
| Married Filing Jointly | ~$30,000 | $96,951 | Usually best for couples |
| Married Filing Separately | ~$15,000 | $48,476 | Narrowest brackets; lose many credits |
| Head of Household | ~$22,500 | $64,851 | Unmarried + qualifying dependent |
When to File MFS
Filing separately is rarely beneficial, but consider it when:
- One spouse has high medical expenses (7.5% of AGI threshold is lower)
- Income-driven student loan repayments are based on individual AGI
- Spouses want to keep tax liability separate for legal reasons
- One spouse has questionable tax positions you don't want to be jointly liable for
Sources
Related Terms
More in Income Tax Basics
Tax Brackets
Progressive rate tiers applied to taxable income.
Marginal Tax Rate
The tax rate on your next dollar of income.
Effective Tax Rate
Your average tax rate across all income.
Taxable Income
Income remaining after deductions, subject to tax.
Adjusted Gross Income (AGI)
Gross income minus above-the-line deductions.
Modified Adjusted Gross Income (MAGI)
AGI with certain deductions added back, used for eligibility tests.
Marriage Penalty & Bonus
Tax impact of filing jointly vs. two singles.
Tax Cuts and Jobs Act (TCJA)
2017 law that lowered rates and doubled the standard deduction.