Idaho has a state income tax, and it applies to most residents and workers
Idaho taxes income earned by residents and by nonresidents who work in the state. The tax rate varies based on your income level — Idaho uses a progressive tax system with rates that climb as your income rises. For 2024, rates range from 1% on the lowest bracket to 5.8% on the highest. If you live in Idaho, work there, or receive income from Idaho sources, you will owe state income tax unless you fall into a specific exemption category.
The state also taxes business income, capital gains, and certain types of investment income. If you are self-employed or own a business in Idaho, you report that income on your state return. Idaho does not tax Social Security benefits, and it offers a pension exemption for certain retirement income — but those rules have specific dollar limits and age requirements that determine whether your particular income qualifies.
Key Takeaways
- Idaho state income tax rates range from 1% to 5.8% depending on your income bracket, and the state uses a progressive system where higher earners pay higher rates.
- You owe Idaho income tax if you are a resident, a nonresident who earned income in Idaho, or someone with Idaho-source income like rental property or business revenue.
- Social Security benefits are not taxed in Idaho, but pension and retirement income may be taxable unless you meet specific age and income thresholds.
- You file Idaho income tax on Form 40, which you submit to the Idaho State Tax Commission by April 15 unless you receive an extension.
Who has to file an Idaho state income tax return
You must file if you are an Idaho resident with income above a certain threshold. For 2024, that threshold depends on your filing status and age — a single person under 65 generally must file if they earned more than $14,600, while a married couple filing jointly must file if their combined income exceeded $29,200. These amounts change each year, so check the current year's threshold on the Idaho State Tax Commission website before you file.
Nonresidents who earned income in Idaho must also file, even if they do not live there. This includes people who worked in Idaho for part of the year, received business income from Idaho sources, or owned rental property in the state. If you moved to or from Idaho during the year, you are considered a part-year resident and must file an Idaho return for the months you lived there.
Some income is exempt from the filing requirement. If your only income was Social Security benefits, you do not have to file an Idaho return. If you had very small amounts of income and no tax was withheld, you may not be required to file — but filing anyway can result in a refund if you overpaid through withholding.
Idaho income tax brackets and rates for 2024
Idaho's income tax system has six tax brackets. The lowest bracket starts at 1% on income up to $1,783 for single filers, and the highest bracket is 5.8% on income over $35,675. The brackets are adjusted each year for inflation, so the dollar amounts change annually. Married couples filing jointly have higher bracket thresholds than single filers.
| Filing Status | Lowest Bracket | Highest Bracket | Top Rate |
|---|---|---|---|
| Single | 1% on income up to $1,783 | 5.8% on income over $35,675 | 5.8% |
| Married Filing Jointly | 1% on income up to $3,566 | 5.8% on income over $71,350 | 5.8% |
| Head of Household | 1% on income up to $2,675 | 5.8% on income over $53,512 | 5.8% |
The brackets mean that not all of your income is taxed at the top rate. If you are single and earn $40,000, you pay 1% on the first $1,783, then 2% on the next bracket, and so on until you reach the 5.8% bracket for income above $35,675. This is called a progressive tax system, and it means your overall tax rate is lower than the top bracket rate.
Retirement income and pension exemptions in Idaho
Idaho does not tax Social Security benefits, which means that income is completely exempt from state tax. However, other types of retirement income have different rules. If you receive a pension from a government employer — such as a teacher's pension or a military retirement — you may be able to exclude some or all of that income from Idaho taxation, depending on your age and when you started receiving the pension.
Private pensions and distributions from retirement accounts like IRAs and 401(k)s are generally taxable in Idaho. There is no blanket exemption for retirement account withdrawals based on age alone. However, if you are over 59½ and receive distributions from certain retirement plans, you may be able to claim a deduction — but the rules are specific and depend on the type of account and when you opened it.
If you receive income from a pension or retirement account, review the Idaho State Tax Commission's guidance on pension exemptions or speak with a tax professional who knows Idaho law. The rules change periodically, and your specific situation — your age, the source of the pension, and when you began receiving it — determines what you owe.
How to file your Idaho state income tax return
You file Idaho income tax on Form 40, the Idaho Individual Income Tax Return. You can file by mail, online through the Idaho State Tax Commission website, or through tax software that supports Idaho returns. The important date is April 15 of the year following the tax year, unless you file for an extension. If you file for an extension, you have until October 15 to submit your return, but any tax you owe is still due by April 15 or you will owe interest and penalties.
When you file, you will need your federal tax information — your federal adjusted gross income from your Form 1040 is the starting point for your Idaho return. You will also need records of any Idaho-specific income, deductions, or credits. If you had income withheld from paychecks, you will need your W-2 forms. If you are self-employed, you will need your Schedule C or Schedule F from your federal return.
You mail your completed Form 40 and any supporting documents to the Idaho State Tax Commission at the address shown on the form. If you file electronically, the return is submitted directly to the state. The state processes returns and issues refunds or bills for additional tax owed. If you are owed a refund, it typically arrives within four to six weeks of filing, though this varies depending on the complexity of your return.
Deductions and credits available to Idaho taxpayers
Idaho allows you to claim either the standard deduction or itemize deductions, just as you do on your federal return. The Idaho standard deduction for 2024 is $14,600 for single filers and $29,200 for married couples filing jointly — these amounts match the federal standard deduction. If you itemize on your federal return, you can itemize on your Idaho return as well, though Idaho does not allow all the same deductions as the federal government.
Idaho offers several tax credits that reduce the amount of tax you owe. These include credits for dependent children, credits for education expenses, and credits for certain types of income. The child and dependent credit is one of the most common — it allows you to reduce your tax liability based on the number of dependents you claim. Credits are more valuable than deductions because they reduce your tax dollar-for-dollar, rather than reducing the income that is taxed.
If you paid estimated tax during the year or had tax withheld from your paychecks, those payments are credited against your final tax liability. If you overpaid, you receive a refund. If you underpaid, you owe the difference. Some taxpayers also claim credits for property taxes paid or for low-income status — review the Form 40 instructions to see which credits explore to your situation.
What happens if you do not file or pay Idaho income tax
If you owe Idaho income tax and do not file or pay by the important date, the state charges interest and penalties. The interest rate is set quarterly and compounds daily. The failure-to-file penalty is typically 5% of the unpaid tax for each month the return is late, up to a maximum of 25%. The failure-to-pay penalty is 0.5% of the unpaid tax for each month the tax remains unpaid, also up to 25%.
The Idaho State Tax Commission can also place a lien on your property, garnish your wages, or seize your bank accounts to collect unpaid tax. If you owe a large amount, the state may refer your case to a collection agency. These enforcement actions can damage your credit and make it difficult to borrow money or rent housing.
If you cannot pay the full amount you owe, contact the Idaho State Tax Commission to discuss payment options. The state offers installment agreements that allow you to pay over time, and it may be willing to reduce or waive penalties if you have a reasonable explanation for the delay. Filing your return on time, even if you cannot pay the full amount, reduces the penalties you face.
Frequently Asked Questions
Does Idaho tax retirement income differently than other states?
Idaho does not tax Social Security benefits, which is common among states. However, pensions and retirement account distributions are taxed unless they meet specific exemptions — particularly government pensions for people over a certain age. Idaho's treatment of retirement income is more restrictive than some states but less restrictive than others. Compare Idaho's rules to your previous state if you recently moved.
What if I worked in Idaho for only part of the year?
You file as a part-year resident and report only the income you earned during the months you lived in Idaho. You will need to separate your W-2 income by state and report only the Idaho portion on your state return. If you moved mid-year, the Idaho State Tax Commission website has worksheets to help you calculate the correct amount.
Can I file my Idaho return electronically?
Yes. The Idaho State Tax Commission allows electronic filing through its website and through most commercial tax software. E-filing is faster than mailing and produces a confirmation that the state received your return. If you file electronically and are owed a refund, it typically arrives faster than a mailed return.
What if I made a mistake on my Idaho return after I filed it?
You can file an amended return using Form 40-X. You must file the amended return within three years of the original return's due date. If the amendment results in a refund, the state will process it. If it results in additional tax owed, you will receive a bill with interest calculated from the original due date.
Do I have to file an Idaho return if I only had Social Security income?
No. Social Security benefits are not taxed in Idaho, so if that was your only income, you do not have to file an Idaho return. However, if you had other income in addition to Social Security, you must file and report the non-Social Security income.