For a Disability Code of 3, the distribution is not subject to the additional 10% tax, but the disability distribution is still included in taxable income.

Per IRS Publication 575 Pension and Annuity Income, page 6:

Disability Pensions

If you retired on disability, you must generally include in income any disability pension you receive under a plan that is paid for by your employer. You must report your taxable disability payments as wages on Form 1040 or 1040-SR, line 1; or Form 1040-NR, line 1a, until you reach minimum retirement age. Minimum retirement age is generally the age at which you can first receive a pension or annuity if you aren't disabled.

TIP: You may be entitled to a tax credit if you were permanently and totally disabled when you retired. For information on this credit, see Pub. 524.

Beginning on the day after you reach minimum retirement age, payments you receive are taxable as a pension or annuity. When you receive pension or annuity payments, you are able to recover your cost or investment. Your cost is generally your net investment in the plan as of your annuity starting date. It doesn't include pre-tax contributions. For more information, see Cost (Investment in the Contract) and Taxation of Periodic Payments, later.

Report the payments on Form 1040, 1040-SR, or 1040-NR, lines 5a and 5b.

To enter this distribution into the TaxAct program: 

1. Sign in to your TaxAct account, then click the My Tax Returns tile.
2. Locate the relevant return, then click Open Return in the Actions column for that return.
3. In the left navigation bar, click Federal.
4. In the Federal Quick Q&A Topics panel, click Retirement Plan Income > IRA, 401(k), and pension plan distributions (Form 1099-R).
5. Click + Add Form 1099-R to create a new form, or click Edit to edit an existing form.
6. Answer the questions until you reach the Enter the remaining details from the Form 1099-R screen. On that screen, click the Box 7 - First Distribution code dropdown, then select 3 - Disability.
7. Scroll down, then click Continue.
8. On the Retirement Plan Income - Disability screen, check the Have not reached minimum retirement age box if you haven't reached your employer's minimum retirement age.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the webpage or document at the time it is accessed.