“Now we subtract. This is where your tax bill really starts to shrink.”

So far in our journey, we’ve covered:

• ✔️ Do you have to file?

• ✔️ What’s your filing status?

• ✔️ What counts as income?

• ✔️ How AGI (Adjusted Gross Income) is calculated

Now we move into the next major phase of the 1040:

Deductions.

This is where we reduce your income before the tax rates are applied.

And this is the moment where people always ask:

“Should I itemize or just take the standard deduction?”

Let’s break it down in real life.

Step 1: From AGI to Taxable Income

Here’s the flow:

Gross Income− Adjustments= AGI− Standard Deduction or Itemized Deductions= Taxable Income

Taxable income is the number your tax bracket applies to.

So the bigger your deduction (legally), the lower your taxable income.

Standard Deduction vs. Itemizing

(Line 12 on the 1040)

In most cases, your tax will be lower if you take whichever deduction is larger.

For most Americans, that’s the standard deduction.

The Standard Deduction: “The Easy Button”

The standard deduction is a flat amount the IRS lets you subtract based on your filing status.

You don’t have to track receipts.

You don’t have to list expenses.

You just claim the number.

Real-life example

Angela (Single)

AGI: $70,000Standard deduction: Let’s say $15,000 (example amount)

Taxable income becomes:

$70,000 − $15,000 = $55,000

She didn’t need to track anything.

Simple.

When You Can’t Take the Standard Deduction

There are a few exceptions where your standard deduction is zero:

1️⃣ Someone claims you as a dependent

If a parent (or someone else) claims you on their return, your standard deduction may be limited.

Example:

College student working part-time — standard deduction is calculated differently.

2️⃣ Married Filing Separately and your spouse itemizes

If your spouse itemizes, you must itemize too — even if your expenses are tiny.

3️⃣ Dual-status aliens

Certain residency situations eliminate eligibility for the standard deduction.

Bigger Standard Deduction Situations

You may qualify for a higher standard deduction if:

• You were born before January 2, 1961 (age-based increase)

• You are legally blind

• Certain qualified disaster losses apply

Example

Mr. Thompson is 67 and single.

He receives a higher standard deduction than a 35-year-old single filer.

Age matters.

Itemized Deductions: “The Detailed Route”

Instead of taking the flat standard deduction, you can choose to list actual expenses on Schedule A.

Common itemized deductions include:

• Mortgage interest

• State and local taxes (SALT cap applies)

• Charitable contributions

• Certain medical expenses (above income thresholds)

• Qualified disaster losses

You only itemize if the total of those expenses exceeds your standard deduction.

Real-Life Comparison

Let’s compare two homeowners.

Person A

Mortgage interest: $8,000

State/local taxes: $9,000

Charity: $2,000

Total itemized = $19,000

If standard deduction is $15,000 →They itemize and deduct $19,000.

Person B

Mortgage interest: $4,000

Taxes: $6,000

Charity: $1,000

Total itemized = $11,000

Standard deduction = $15,000 →They take standard instead.

Bigger number wins.

Always.

Strategy Insight: Why Most People Take Standard

Tax law changes increased the standard deduction significantly in recent years.

That means fewer people itemize.

But here’s the key:

Even if you take the standard deduction, you still need to understand itemizing — because:

• Buying a house changes the math.

• Large charitable giving changes the math.

• Disaster losses change the math.

Strategy shifts with life changes.

Line 13a: Qualified Business Income (QBI) Deduction

Now we enter something powerful for business owners.

If you have:

• Sole proprietorship income

• S corporation income

• Partnership income

• Certain rental income

• REIT or PTP income

You may qualify for the Qualified Business Income Deduction (Section 199A).

This deduction can be up to 20% of qualified business income.

And here’s what makes it interesting:

It comes after standard or itemized deductions.

Real-Life Example

Jasmine runs a consulting business.

Net business profit: $100,000

If she qualifies, she may deduct up to 20%:

$100,000 × 20% = $20,000 deduction

That reduces taxable income further.

That’s powerful.

But eligibility depends on:

• Taxable income thresholds

• Type of business

• W-2 wage and asset limits at higher income levels

If income is below certain thresholds, calculation is simple (Form 8995).Above those levels, it gets more complex (Form 8995-A).

This is where strategy really matters for self-employed readers.

Line 13b: New and Additional Deductions

Depending on the tax year, additional deductions may apply from Schedule 1-A, including:

• No tax on tips (if eligible)

• No tax on overtime (if eligible)

• Car loan interest deduction (if eligible)

• Enhanced deduction for seniors (if applicable)

These are layered deductions — meaning they further reduce taxable income if you qualify.

Let’s Put It All Together

Let’s build a full example:

Marcus (Married Filing Jointly)

Gross Income: $130,000

Adjustments (HSA + IRA): $5,000

AGI = $125,000

Standard Deduction: $30,000 (example figure for MFJ)

Taxable income before QBI = $95,000

Marcus also has $40,000 in qualified business income.

QBI deduction (20%) = $8,000

Final taxable income =$95,000 − $8,000 = $87,000

That’s the number tax brackets apply to.

Not the original $130,000.

Not the AGI.

But the final taxable income.

See how much movement happened?

Why This Section Matters for Your Life

Deductions are not just about math.

They affect:

• Whether you qualify for credits

• Whether your QBI deduction phases out

• Your Medicare premiums (for some taxpayers)

• Student loan repayment calculations

• Marketplace healthcare subsidies

Everything builds on this number.

Questions to Ask Yourself

• Do I own a business and qualify for QBI?

• Do my itemized deductions actually exceed the standard?

• Has a life change (home purchase, marriage, disaster loss) changed my deduction strategy?

• Am I leaving legal deductions unused?

Next in the Series

Now that we’ve reduced income to taxable income, next we’ll answer:

• How tax brackets actually work

• Why being “in a higher bracket” doesn’t mean all your income is taxed at that rate

• How credits reduce tax dollar-for-dollar

Because once we reach that point, you’ll fully understand how your refund — or balance due — is created.

And that’s when tax stops feeling mysterious.