What will your tax liability be?

When it comes to income taxes, nothing is simple. For example, first you need to consider your marginal tax rate -- this is the regular rate you'll pay on your next dollar of "ordinary income" (salary, business income, interest and more).

Then there’s the alternative minimum tax (AMT), which was designed to ensure wealthy taxpayers with “excessive” deductions would pay some income tax. The top AMT rate is lower than the top regular income tax rate on ordinary income. (See the Charts “2017 individual income tax rate schedules” and “2018 individual income tax rate schedules.”) But the AMT rate typically applies to a higher taxable income base. So if you plan only for regular income taxes, it can result in unwelcome tax surprises.

You also need to consider the various tax deductions and credits that could save you taxes. On the other hand, income-based phaseouts and other limits can reduce or eliminate the benefits of these breaks, effectively increasing your marginal tax rate.

With the Tax Cuts and Jobs Act (TCJA), tax planning just got more complicated. While one of the intentions of lawmakers was to simplify the tax code, at least for 2018 things will be more complicated as everyone gets familiar with the changes and their impact. Strategies that made sense in the past may no longer make sense, while new tax-saving opportunities may be available.

The TCJA generally reduces individual tax rates for 2018 through 2025 and expands some tax breaks. But it also reduces or eliminates breaks that had been valuable to many taxpayers. The total impact of all of these changes is what will ultimately determine whether you see reduced taxes and what tax strategies will make sense for you this year, such as the best ways to time income and expenses.

AMT triggers

Before taking action to time income or expenses, you should determine whether you’re
already likely to be subject to the AMT — or whether the actions you’re considering might
trigger it. Many deductions used to calculate regular tax aren’t allowed under the AMT (see the Charts “Regular tax vs. AMT: What’s deductible for 2017?” and “Regular tax vs. AMT: What’s deductible for 2018?) and thus can trigger AMT liability. Some income items also might trigger or increase AMT liability:

  • Long-term capital gains and dividend income, even though they’re taxed at the same rate for both regular tax and AMT purposes,
  • Accelerated depreciation adjustments and related gain or loss differences when assets are sold, and
  • Tax-exempt interest on certain private-activity municipal bonds. (See the AMT Alert under “Income investments.”)

Finally, in certain situations incentive stock option (ISO) exercises can trigger significant AMT liability.

If you pay AMT in one year on deferral items, such as depreciation adjustments, passive activity adjustments or the tax preference on ISO exercises, you may be entitled to a credit in a subsequent year.

In effect, this takes into account timing differences that reverse in later years.

Fortunately, the TCJA significantly increases the AMT exemptions and exemption phaseout income ranges for 2018 through 2025. (See the Charts “2017 individual income tax rate schedules.” and “2018 individual income tax rate schedules.”)That means fewer taxpayers will be at AMT risk for 2018.

Avoiding or reducing AMT

If your income is high enough that you’re at AMT risk for 2018, with proper planning, you may be able to avoid the AMT, reduce its impact or even take advantage of its lower maximum rate. (See the Chart “2018 individual income tax rate schedules.”)

To determine the right timing strategies for your situation, work with your tax advisor to assess whether:

You could be subject to the AMT this year. Consider accelerating income and short-term capital gains into this year, which may allow you to benefit from the lower maximum AMT rate. Also consider deferring expenses you can’t deduct for AMT purposes until next year — you may be able to preserve those deductions.

Additionally, if you defer expenses you can deduct for AMT purposes to next year, the deductions may become more valuable because of the higher maximum regular tax rate. Finally, carefully consider the tax consequences of exercising ISOs.

You could be subject to the AMT next year. Consider taking the opposite approach. For instance, defer income to next year, because you’ll likely pay a relatively lower AMT rate. And prepay expenses that will be deductible this year but that won’t help you next year because they’re not deductible for AMT purposes. Also, before year end consider selling any private activity municipal bonds whose interest could be subject to the AMT.

Timing income and expenses

Smart timing of income and expenses can reduce your tax liability, and poor timing can unnecessarily increase it.

When you don’t expect to be subject to the AMT in the current year or the next year, deferring income to the next year and accelerating deductible expenses into the current year typically is a good idea. Why? Because it will defer tax, which is usually beneficial.

But when you expect to be in a higher tax bracket next year — or you expect tax rates to go up — the opposite approach may be beneficial: Accelerating income will allow more income to be taxed at your current year’s lower rate. And deferring expenses will make the deductions more valuable, because deductions save more tax when you’re subject to a higher tax rate.

Whatever the reason behind your desire to time income and expenses, here are some income items whose timing you may be able to control:

And here are some potentially controllable expenses:

  • State and local income taxes,
  • Property taxes,
  • Mortgage interest,
  • Margin interest, and
  • Charitable contributions.

Warning: Be aware that, under the TJCA, some of these deductions are subject to tighter limit for 2018 than applied in 2017.

The standard deduction vs. itemized deductions

Taxpayers can choose to itemize certain deductions on Schedule A or take the standard deduction based on their filing status instead. Itemizing deductions when the total will be larger than the standard deduction saves tax, but it makes filing more complicated.
For 2017, the standard deductions are $6,350 for singles and separate filers, $9,350 for head of household filers, and $12,700 for married couples filing jointly.

The TCJA nearly doubles the standard deductions for 2018 to $12,000 for singles and separate filers, $18,000 for heads of households, and $24,000 for joint filers. (These amounts will be adjusted for inflation for 2019 through 2025.)

For 2018, some taxpayers who’ve typically itemized deductions in the past may be better off taking the standard deduction. Why? The larger standard deduction combined with the reduction or elimination of some itemized deductions mean more taxpayers will find that the standard deduction exceeds their itemized deduction. This will be another important factor to consider when you evaluate timing strategies for 2018.

Miscellaneous itemized deductions

Many expenses that may qualify as miscellaneous itemized deductions on your 2017 return are deductible for regular tax purposes only to the extent they exceed, in aggregate, 2% of your AGI, such as:

  • Deductible investment expenses, including advisory fees, custodial fees and publications,
  • Professional fees, such as tax planning and preparation, accounting, and certain legal fees, and
  • Unreimbursed employee business expenses, including travel, meals, entertainment and vehicle costs.

Warning: For 2018 through 2025, the TCJA suspends the deduction for these expenses.

Health care breaks

Under the the TCJA, if 2017 or 2018 medical expenses not paid via tax-advantaged accounts or reimbursable by insurance exceed 7.5% of your AGI, you can deduct the excess amount. The threshold had been 10%, and it's scheduled to return to 10% beginning in 2019.

Eligible expenses may include:

  • Health insurance premiums,
  • Long-term care insurance premiums (limits apply),
  • Medical and dental services,
  • Prescription drugs, and
  • Mileage (17 cents per mile driven for health care purposes in 2017,
    18 cents per mile driven in 2018)

Consider bunching medical procedures (and any other services and purchases whose timing you can control without negatively affecting your or your family’s health) into 2018 to take advantage of the 7.5% floor and potentially enjoy a larger deduction. Also keep in mind that if one spouse has high medical expenses and a relatively lower AGI, filing separately may allow that spouse to exceed the AGI floor and deduct some medical expenses that wouldn’t be deductible if the couple filed jointly.

Expenses that are reimbursable by insur­ance or paid through a tax-advantaged account such as the following aren’t deductible:

HSA. If you’re covered by a qualified high-deductible health plan, you can contribute pretax income to an employer-sponsored Health Savings Account — or make deductible contributions to an HSA you set up yourself — up to $3,450 for self-only coverage for 2018 (up from $3,400 for 2017) and $6,850 for family coverage for 2018 (up from $6,750 for 2017). Moreover, for 2018 (same as 2017), you may contribute an additional $1,000 if you're age 55 or older.

HSAs can bear interest or be invested, growing tax-deferred similar to an IRA. Withdrawals for qualified medical expenses are tax-free, and you can carry over a balance from year to year.

FSA. You can redirect pretax income to an employer-sponsored Flexible Spending Account up to an employer-determined limit (not to exceed $2,650 for plan years beginning in 2018, up from $2,600 for 2017). The plan pays or reimburses you for qualified medical expenses. With limited exceptions, you have to make your election before the start of the plan year. What you don’t use by the end of the plan year, you generally lose — though your plan might allow you to roll over up to $500 to the next year. Or it might give you a 2 ½-month grace period to incur expenses to use up the previous year’s contribution. If you have an HSA, your FSA is limited to funding certain “permitted” expenses.

Deduction for state and local income tax or sales tax

Individuals generally can take an itemized deduction for either state and local income tax or state and local sales tax. For most taxpayers, deducting state and local income taxes will provide more tax savings. But deducting sales tax can be more valuable to taxpayers residing in states with no or low income tax or who purchase a major item, such as a car or boat.

Except for major purchases, you don’t have to keep receipts and track all the sales tax you actually paid during the year. Your deduction can be determined using an IRS sales tax calculator that will base the deduction on your income and the sales tax rates in your locale plus the tax you actually pay on major purchases.

For 2018 through 2025, however, your entire deduction for state and local taxes -- including property tax and either income tax or sales tax -- is limited to $10,000.

Personal exemption phaseout and itemized deduction reduction

If your 2017 AGI exceeds the applicable threshold, your personal exemptions will be phased out and your itemized deductions reduced. The thresholds are $261,500 (single), $288,650 (head of household), $313,800 (joint filer) and $156,900 (married filing separately).

The personal exemption phaseout reduces 2017 exemptions by 2% for each $2,500 (or portion thereof) by which a taxpayer’s AGI exceeds the applicable threshold (2% for each $1,250 for married taxpayers filing separately).

The itemized deduction limitation reduces otherwise allowable 2017 deductions by 3% of the amount by which a taxpayer’s AGI exceeds the applicable threshold (not to exceed 80% of otherwise allowable deductions). It doesn’t apply, however, to deductions for medical expenses, investment interest, or casualty, theft or wagering losses.

The TCJA has suspended personal exemptions for 2018 through 2025. It also has suspended the itemized deduction reduction for these years. So you don't need to consider the exemption phaseout or deduction reduction in your 2018 planning.

Employment taxes

In addition to income tax, you must pay Social Security and Medicare taxes on earned income, such as salary and bonuses. The 12.4% Social Security tax applies to earned income up to the Social Security wage base of $128,400 for 2018 (up from $127,200 for
2017). All earned income is subject to the 2.9% Medicare tax. Both taxes are split equally between the employee and the employer.

Self-employment taxes

If you’re self-employed, your employment tax liability typically doubles, because you also must pay the employer portion of these taxes. The employer portion of self-employment taxes paid (6.2% for Social Security tax and 1.45% for Medicare tax) is deductible above the line.

As a self-employed taxpayer, you may benefit from other above-the-line deductions as well. You can deduct 100% of health insurance costs for yourself, your spouse and your dependents, up to your net self-employment income. You also can deduct contributions to a retirement plan and, if you’re eligible, an HSA for yourself. Above-the-line deductions are particularly valuable because they reduce your AGI and modified AGI (MAGI), which are the triggers for certain additional taxes and the phaseouts of many tax breaks.

Additional 0.9% Medicare tax

Another employment tax that higher-income taxpayers must be aware of is the additional 0.9% Medicare tax. It applies to FICA wages and self-employment income exceeding $200,000 per year ($250,000 for married filing jointly and $125,000 for married filing separately).

Note that there’s no employer portion of this tax. So unlike the Social Security tax and the regular Medicare tax, the additional Medicare tax doesn’t double for the self-employed. But this also means that no portion of the tax is deductible above the line against self-employment income.

Also consider the withholding rules. Employers are obligated to withhold the additional tax beginning in the pay period when wages exceed $200,000 for the calendar year — without regard to an employee’s filing status or income from other sources. So your employer might withhold the tax even if you aren’t liable for it — or it might not withhold the tax even though you are liable for it.

If you don’t owe the tax but your employer is withholding it, you can claim a credit on your income tax return for the year the tax was withheld. If you do owe the tax but your employer isn’t withholding it, consider filing a W-4 form to request additional income tax with­holding, which can be used to cover the shortfall and avoid interest and penalties. Or you can make estimated tax payments.

Employment taxes for owner-employees

There are special considerations if you’re a business owner who also works in the business, depending on its structure:

Partnerships and limited liability companies. Generally, all trade or business income that flows through to you for income tax purposes is subject to self-employment taxes — even if the income isn’t actually distributed to you. But such income may not be subject to self-employment taxes if you’re a limited partner or an LLC member whose ownership is equivalent to a limited partnership interest. Whether the additional 0.9% Medicare tax on earned income or the 3.8% net investment income tax (NIIT) will apply also is complex to determine. So, check with your tax advisor.

S corporations and C corporations. Only income you receive as salary is subject to employment taxes and, if applicable, the 0.9% Medicare tax.

Warning: The IRS is cracking down on misclassification of corporate payments to shareholder-employees, so tread carefully.

Estimated payments and withholding

You can be subject to penalties if you don’t pay enough tax during the year through estimated tax payments and withholding. Here are some strategies to help avoid underpayment penalties:

Know the minimum payment rules. For you to avoid penalties, your estimated payments and withholding must equal at least 90% of your tax liability for the year or 110% of your tax for the previous year (100% if your AGI for the previous year was $150,000 or less or, if married filing separately, $75,000 or less).

Use the annualized income installment method. This method often benefits taxpayers who have large variability in income by month due to bonuses, investment gains and losses, or seasonal income (especially if it’s skewed toward the end of the year). Annualizing computes the tax due based on income, gains, losses and deductions through each estimated tax period.

Estimate your tax liability and increase withholding. If as year end approaches you determine you’ve underpaid, consider having the tax shortfall withheld from your salary or year end bonus by December 31. Because withholding is considered to have been paid ratably throughout the year, this is often a better strategy than making up the difference with an increased quarterly tax payment, which may still leave you exposed to penalties for earlier quarters.

Warning: You also could incur interest and penalties if you’re subject to the additional 0.9% Medicare tax and it isn’t withheld from your pay and you don’t make sufficient estimated tax payments.