Colorado Inheritance Tax Forms: Step-by-Step Guide

If someone close to you recently passed away and left behind property or assets in Colorado, you might be wondering what tax forms need to be filed and how to handle the paperwork. The process can feel overwhelming, especially while you're grieving. Getting the forms right the first time saves you from penalties, delays in distributing the estate, and unnecessary stress. This step-by-step breakdown will walk you through what's actually required so you can move forward with confidence.

Does Colorado Have an Inheritance Tax?

Here's something that surprises many people: Colorado does not have a state-level inheritance tax or estate tax. The state repealed its estate tax effective for deaths occurring after December 31, 2004. That means when someone dies as a Colorado resident, there is no separate Colorado tax form you need to file on inherited assets.

However, that doesn't mean you're done with paperwork. There are still federal estate tax obligations, probate court filings, and income tax considerations tied to inherited property. Understanding what applies to your situation is the first step. You can learn more about the full scope of estate tax filing requirements after a death in Colorado to get the bigger picture before diving into specific forms.

What Forms Might You Still Need to File?

Even without a Colorado state estate tax, several forms may come into play depending on the size of the estate and the types of assets involved:

Federal Estate Tax Return (IRS Form 706): Required only if the gross estate exceeds the federal exemption threshold, which is $13.61 million per individual for 2024. Most estates won't trigger this.
Federal Estate Income Tax Return (IRS Form 1041): If the estate earns income after the decedent's death like rental income, interest, or dividends this form must be filed.
Colorado Individual Income Tax Return (Form 104): Filed for the deceased person's final year of income, covering January 1 through the date of death.
Probate court filings: Colorado probate courts require their own set of documents, which vary by county.

If you're dealing with estate paperwork at the county level, our guide on Colorado probate court estate tax documents breaks down what each form means and where to submit it.

How Do You File the Federal Estate Tax Return (Form 706)?

Most Colorado estates won't need to file Form 706 because of the high federal exemption. But if the estate is large enough, here's how the process works:

Step 1: Determine the Gross Estate Value

Add up the fair market value of everything the decedent owned or had interest in at the time of death. This includes real estate, bank accounts, investments, retirement accounts, life insurance proceeds payable to the estate, business interests, and personal property like vehicles and jewelry. Use the value as of the date of death, not the original purchase price.

Step 2: Calculate Allowable Deductions

Subtract deductions from the gross estate. Common deductions include:

Funeral expenses
Outstanding debts and mortgages
Administrative costs (attorney fees, executor fees, appraiser fees)
Charitable bequests
The marital deduction for property passing to a surviving spouse

Step 3: Apply the Federal Exemption

Each individual gets a lifetime exemption against estate and gift taxes. For 2024, that amount is $13.61 million. If your taxable estate is below this number, no federal estate tax is owed though you may still choose to file Form 706 to elect portability of a deceased spouse's unused exemption.

Step 4: Complete the Form

IRS Form 706 is lengthy typically 20+ pages. It requires detailed schedules for assets, deductions, transfers, and prior taxable gifts. You'll need accurate appraisals for real estate and valuable personal property. The form must be filed within nine months of the date of death, with an optional six-month extension using Form 4768.

Step 5: File and Pay Any Tax Due

Mail the completed form to the IRS service center designated for your filing. If tax is owed, payment is due at the time of filing. Electronic filing is not available for Form 706.

How Do You Handle the Estate Income Tax Return (Form 1041)?

If the estate earns any income after the date of death interest on bank accounts, rental income from property, dividends from stocks you'll need to file Form 1041. Here's the process:

Get an EIN: Apply for an Employer Identification Number for the estate using the IRS online tool or Form SS-4. The estate is a separate tax entity and can't use the deceased person's Social Security number.
Open an estate bank account: All estate income should flow through this account for clean recordkeeping.
Track income and expenses: Record all income received by the estate and any deductible expenses like administrative costs.
File Form 1041: Due by April 15 of the year following the tax year in question. The estate can also use a fiscal year rather than a calendar year.
Issue Schedule K-1s: If income is distributed to beneficiaries, you'll provide each beneficiary a Schedule K-1 showing their share, which they report on their personal tax returns.

What About the Decedent's Final Colorado Income Tax Return?

The deceased person needs a final state and federal income tax return filed for the year they died. For Colorado, use Form 104. Report all income received from January 1 through the date of death. If a refund is due, you'll need to attach Form 1310 (Statement of Person Claiming Refund Due a Deceased Taxpayer) to the federal return.

This is separate from the estate income tax return. Don't confuse the two one covers the person's income before death, the other covers the estate's income after death.

What Probate Court Documents Are Required?

Colorado has its own probate process, and the court requires specific filings regardless of whether federal estate taxes apply. You'll typically need to file a petition to open probate, an inventory of assets, and periodic accountings. The exact documents and deadlines vary by county, so it's worth reviewing filing deadlines by county to make sure you don't miss anything.

For a full explanation of the forms involved, see our breakdown of how to fill out Colorado inheritance tax forms.

What If the Decedent Owned Property in Another State?

This is where things get more complicated. If the deceased person owned real estate or other assets in a state that does have an estate or inheritance tax like Oregon, Massachusetts, New Jersey, or several others you may need to file an estate or inheritance tax return in that state. This is separate from any Colorado filings.

Nonresidents who owned Colorado property may also face specific filing obligations. Our article on nonresident estate tax filing obligations in Colorado covers what to expect if you're managing an estate from another state.

Common Mistakes People Make With Estate Tax Forms

Missing the filing deadline: Form 706 is due nine months after death. If you need more time, file for an extension before the deadline passes you get an automatic six months with Form 4768.
Using incorrect asset values: You must use fair market value as of the date of death, not what the asset was purchased for. Get professional appraisals for real estate and high-value items.
Confusing inheritance tax with estate tax: These are different things. An estate tax is paid by the estate before distribution. An inheritance tax is paid by the person who receives assets. Colorado has neither at the state level.
Forgetting to file the decedent's final income tax return: This is a separate obligation from the estate return and easy to overlook.
Not electing portability: If a surviving spouse exists and the deceased spouse's estate doesn't use all of their federal exemption, filing Form 706 even if no tax is owed lets the surviving spouse claim the unused portion. This can save significant taxes later.
Mixing estate funds with personal funds: Keep everything separate through a dedicated estate bank account and EIN.

Do You Need a Tax Professional or Attorney?

For straightforward estates with no federal estate tax filing requirement and no real estate or complex assets, you may be able to handle the final income tax return on your own. But if any of the following apply, hire a professional:

The gross estate is close to or exceeds the federal exemption
There's real estate in multiple states
There are trusts involved
The estate generates significant post-death income
Beneficiaries disagree about asset distribution
You want to elect portability

An estate attorney and a CPA who handles estate tax returns can work together to make sure everything is filed correctly. According to the IRS guidance on estate tax, errors on Form 706 can result in penalties and interest.

What Should You Do Right Now?

Here's a practical checklist to get started:

Gather all financial documents for the deceased bank statements, investment accounts, property deeds, life insurance policies, retirement account statements, and outstanding debts.
Determine the gross estate value to see if a federal estate tax return is required.
Apply for an EIN for the estate through the IRS website if you'll be filing Form 1041 or need an estate bank account.
File the petition to open probate in the appropriate Colorado county court within the required timeframe.
Mark your calendar with the nine-month filing deadline for Form 706 (if applicable) and the filing deadline for the final income tax returns.
Consult a CPA or estate attorney if the estate has complex assets, multiple state property, or any uncertainty about filing requirements.

Don't wait until the last minute to organize the paperwork. The sooner you start gathering documents and identifying which forms apply, the smoother the process will be.