Figures: tax year 2026
The applications use original FreeFellow wording and illustrative client facts.
Automated diagnostic and validation checks identify inconsistent amounts, missing fields or incompatible classifications. A flag is evidence of a potential discrepancy, rather than a legal conclusion. Form 1040 accuracy requires resolving the flag against the underlying source.
A completed diagnostic record identifies the flag, supporting evidence, cause, adjustment, downstream recalculation and disposition. Valid alerts are corrected at the source mapping or input level. False positives are cleared with a documented explanation, while unresolved evidence gaps remain open.
Common mistakes
- Confusing contribution with deduction. Lena’s $4,000 contribution remains permissible after employer participation eliminates its deduction.
- Deducting excluded employer contributions. Leah’s $4,000 HSA deposits contain only $3,000 of deductible personal contributions.
- Using the casualty percentage. Leah’s medical floor is ; the 10% casualty floor does not apply.
Bottom line
- Adjustments determine AGI; standard, itemized, additional and QBI deductions determine taxable income afterward.
- Retirement contribution eligibility and current deductibility require separate decisions.
- Excluded employer contributions and business expenses already deducted cannot receive a second deduction.
- Personal deductions require eligibility and timing decisions before reimbursements, percentage floors and dollar ceilings.
Exam shortcut
Source review starts with account type, payment date and funding source, identifying amounts already excluded from wages or deducted on a business schedule. Retirement analysis establishes compensation eligibility before employer-plan coverage. A Roth label resolves the current deduction question immediately. Itemized-deduction analysis establishes eligibility, removes reimbursements and applies category limitations before comparing the permitted deduction routes. QBI analysis first establishes taxable income before the deduction.
The full lesson (about 16,231 words, 108 min read) adds 27 worked examples, all 6 common mistakes, a self-check, free in the app.
Learning objectives
- IV.C1
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