Dear Savvy Senior: What are the IRS income tax filing requirements for retirees this tax season? My income dropped way down when I had to retire last year, so I’m wondering if I need to file a tax return. — Retired Ron

Dear Ron: Whether or not you are required to file a federal income tax return this year depends on how much you earned in 2018, the source of that income, your age and your filing status.

Here’s a rundown of this tax season’s IRS tax filing requirement thresholds. For most people, this is pretty straightforward. If your 2018 gross income — which includes all taxable income, not counting your Social Security benefits, unless you are married and filing separately — was below the threshold for your filing status and age, you may not have to file. But if it’s over, you will.

>> Single: $12,000 ($13,600 if you’re 65 or older by Jan. 1, 2019).

>> Married filing jointly: $24,000 ($25,300 if you or your spouse is 65 or older; or $26,600 if you’re both over 65).

>> Married filing separately: $5 at any age.

>> Head of household: $18,000 ($19,600 if age 65 or older).

>> Qualifying widow(er) with dependent child: $24,000 ($25,300 if age 65 or older).

To get a detailed breakdown on federal filing requirements, along with information on taxable and nontaxable income, call the IRS at 800-829-3676 and ask them to mail you a free copy of the “Tax Guide for Seniors” (publication 554) or see IRS.gov/pub/irs-pdf/p554.pdf.

There are some financial situations that require you to file a tax return, even if your gross income falls below the requirements. For example, if you earned more than $400 from self-employment, owe any special taxes like an alternative minimum tax or get premium tax credits because you, your spouse or a dependent is enrolled in a Health Insurance Marketplace (Obamacare) plan, you’ll need to file.

You’ll also need to file if you’re receiving Social Security benefits, and one-half of your benefits plus your other gross income and any tax-exempt interest exceeds $25,000, or $32,000 if you’re married and filing jointly.

To figure all this out, the IRS offers an interactive tax assistant tool on its website that asks a series of questions that will help you determine if you’re required to file, or if you should file because you’re due a refund. It takes less than 15 minutes to complete.

You can access this tool at IRS.gov/filing — click on “Do I Need to File?” Or, you can get assistance over the phone by calling the IRS helpline at 800-829-1040. You can also get face-to-face help at a Taxpayer Assistance Center. See IRS.gov/localcontacts or call 800-829-1040 to locate a center near you.

Even if you’re not required to file a federal tax return this year, don’t assume that you’re also excused from filing state income taxes. The rules for your state might be very different. See Taxadmin.org/state-tax-agencies.