(CBS Philadelphia) — The new Child Tax Credit may change some parents’ lives. Starting on July 15, the Internal Revenue Service (IRS) will send out up to $300 per kid per month. The payment schedule only extends through the end of 2021. But the whole Credit could come to total more than any previous stimulus check. And it could continue beyond this year, if the proposed American Families Plan passes in its current form. But who qualifies for the payments, and how can someone be sure the money arrives?

Who Qualifies For A Monthly Payment?

For parents of young children up to age five, the IRS will pay $3,600 per child. Half of it will come as six monthly payments, and half as a 2021 tax credit. That total changes to $3,000 for each child ages six through 17. The IRS will make a one-time payment of $500 for dependents age 18 or fulltime college students up through age 24.

READ MORE: Child Tax Credit Update: Here’s How You Opt Out Of Advance Monthly Payments

Advance Child Tax Credit payments will be based on the modified adjusted gross income (AGI) from a parent or parents’ 2020 tax filing. (AGI is the sum of one’s wages, interest, dividends, alimony, retirement distributions and other sources of income minus certain deductions, such as student loan interest, alimony payments and retirement contributions.) The amount phases out at a rate of $50 for every $1,000 of annual income beyond $75,000 for an individual and beyond $150,000 for a married couple. The benefit will be fully refundable. In other words, it will not depend on the recipient’s current tax burden. Qualifying families will receive the full amount, regardless of what they owe in taxes. There is no limit to the number of dependents that can be claimed.

As an example, suppose a married couple has a four-year-old child and an eight-year-old child and showed an annual joint income of $120,000 on their 2020 taxes. The IRS would send them a monthly check for $550 starting in July. That’s $300 per month ($3,600 / 12) for the younger child and $250 per month ($3,000 / 12) for the older child. Those checks would last through December. The couple would then receive the $3,300 balance — $1,800 ($300 X 6) for the younger child and $1,500 ($250 X 6) for the older child — as part of their 2021 tax refund.

Parents of a child who ages out of an age bracket will be paid the lesser amount. That means if a five-year-old turns six in 2021, the parents will receive a total credit of $3,000 for the year, not $3,600. Likewise, if a 17-year-old turns 18 in 2021, the parents will receive $500, not $3,000.

An income increase in 2021 to an amount above the $75,000 ($150,000) threshold could lower a household’s Child Tax Credit. The IRS has confirmed that they’ll soon allow claimants to adjust their income and custodial information online, thus lowering their payments. Failure to do so could increase one’s tax bill or reduce one’s tax refund once 2021 taxes are filed.

Eligibility requires that the dependent be a part of the household for at least half of the year and be at least half supported by the taxpayer. A taxpayer who makes above $95,000 ($170,000) — where the income limits phase out entirely– will not be eligible for the expanded credit. But they can still claim the existing $2,000 credit per child.

READ MORE: Child Tax Credit Update: What You Need To Know

Families that may be eligible received a qualifying letter in the first half of June. It read, in part, “If you’re eligible for advance CTC payments and want to receive these payments, you don’t need to take any action. You will receive a letter with more details.”

How To Ensure You Receive A Monthly Payment

If a parent has filed taxes for 2019 and/or 2020 and meets the qualifications outlined above, nothing more needs to be done. The IRS has the necessary information. They will automatically start issuing payments in the near future.

If a parent is uncertain that they qualify, they can check the recently launched Child Tax Credit Eligibility Assistant. The tool will walk a taxpayer through a series of questions to determine if they meet the basic requirements. It is necessary to have one’s tax return handy or, barring that, some basic information about income and qualifying children.

Many eligible parents do not file taxes. For this reason, the IRS has also set up the Child Tax Credit Non-Filer Sign-Up Tool. The portal allows parents who don’t typically file taxes to provide basic information about themselves. That information includes their name, address, email address, date of birth, and social security number. The IRS will then use the provided information to verify eligibility and automatically start issuing monthly payments.

The IRS has recently launched the Child Tax Credit Update Portal as well. This tool allows a potential recipient to check their eligibility, see if they qualify for advance payments, update direct deposit information, and unenroll from monthly payments. Unenrolling from monthly payments means the taxpayer will receive the entire credit when they file their 2021 taxes.

MORE NEWS: Child Tax Credit Latest: How To Use The IRS’s Update Portal

First published Thursday, June 24, 2021 at 6:21 p.m. ET.