To calculate a CSPA age, you take the child’s biological age on the date an immigrant visa first becomes available and subtract the number of days the underlying petition was pending. If the result is under 21 and the child is unmarried, the child keeps their classification as a child under the Child Status Protection Act, even if they have already turned 21 in real life.
The formula looks like this:
Age on visa availability date − Days the petition was pending = CSPA age
That formula governs family preference (F1, F2A, F2B), employment-based derivatives, and diversity visa derivatives. It does not apply to immediate relatives of U.S. citizens or to derivative refugees and asylees, whose ages freeze on a fixed date instead. Those exceptions are covered further down.
The Three Numbers You Need
The formula has two moving parts and one policy question that affects the first part. Get each right and the math is simple.
Biological Age on the Visa Availability Date
This is the child’s actual age on the day an immigrant visa number first becomes available for their preference category and country of chargeability. You find that date on the Department of State’s monthly Visa Bulletin. A visa is considered available for you in a given month when your priority date is earlier than the cutoff date listed for your category and country.
Calculate the age in years, months, and days. Days matter, because the subtraction can land within weeks of the 21st birthday.
Days the Petition Was Pending
Pending time is the number of days between the day the underlying petition was filed and the day it was approved. For family cases, that runs from the Form I-130 filing date to its approval date. For employment-based cases, it runs from the Form I-140 filing date to its approval date. The filing date appears on the receipt notice; the approval date appears on the Form I-797 approval notice.
Priority date and pending time are not the same thing. In employment-based cases requiring a labor certification, your priority date may be the date the Department of Labor accepted the labor certification for processing, but the pending time subtracted in the CSPA formula is still the I-140 filing-to-approval window. The priority date tells you where you stand in line; the pending time is what shrinks your CSPA age.
Which Visa Bulletin Chart Sets the Availability Date
The Visa Bulletin publishes two charts each month: Final Action Dates and Dates for Filing. Which one USCIS uses when calculating your CSPA age depends on when you filed for adjustment of status.
For adjustment of status applications filed on or after August 15, 2025, USCIS uses only the Final Action Dates chart. For applications that were already pending with USCIS before August 15, 2025, the earlier February 2023 policy still applies: when USCIS designated the Dates for Filing chart for accepting adjustment applications, that chart was also used for the CSPA age calculation. Because the Dates for Filing chart usually shows earlier dates, the pre-August-2025 policy was more generous.
If you missed the window but can show extraordinary circumstances for not filing before August 15, 2025, USCIS may still calculate your CSPA age under the earlier policy.
A Worked Example
A lawful permanent resident files a Form I-130 for their unmarried child on February 1, 2016. USCIS approves the petition on February 1, 2017. The child was born on July 1, 2003. An immigrant visa becomes available on January 1, 2025.
Biological age on the visa availability date: 21 years and 6 months.
Petition pending time: one year (February 1, 2016 to February 1, 2017).
CSPA age: 21 years, 6 months, minus 1 year, equals 20 years and 6 months. Under 21. The child keeps child classification.
Change one input and the outcome flips. If that same petition had been pending only three months, the CSPA age would be 21 years and 3 months, and the child would age out. Every day of processing time counts against you or for you.
When the Formula Doesn’t Apply
Three groups of beneficiaries eligible for CSPA protection use rules other than the subtraction formula. If any of these describes your case, do not run the formula.
Immediate relatives of U.S. citizens. If a U.S. citizen parent files a Form I-130 for you, your age freezes on the date USCIS receives the petition. If you were under 21 on the filing date, you will not age out. The subtraction formula is not used at all. The same freeze-on-filing rule applies to VAWA self-petitioners on Form I-360 and their derivative children, and to K-2 and K-4 nonimmigrants whose U.S. citizen stepparent files an I-130.
Derivative refugees and asylees. Age freezes on a fixed date tied to the principal parent’s application: for derivative refugees, the date of the principal parent’s interview with a USCIS officer (the Form I-590 filing date); for derivative asylees, the date the principal parent filed Form I-589. If the child was under 21 on that date, they do not age out.
Diversity visa derivatives. The formula applies, but the inputs are defined differently. The visa availability date is the first day the Department of State can allocate a visa number based on the principal’s rank number. The pending time is the number of days between the start of the DV registration period and the date of the DV selection letter. Subtract that pending time from the child’s biological age on the visa availability date.
The One-Year “Sought to Acquire” Requirement
A favorable CSPA age is not enough on its own. Federal law also requires the beneficiary to seek to acquire lawful permanent resident status within one year of the visa becoming available. Miss that one-year window and CSPA protection disappears, even with a calculated age well under 21.
You satisfy the requirement by taking one of these actions within one year of visa availability:
- Filing Form I-485 (Application to Register Permanent Residence or Adjust Status) if you are in the United States
- Submitting a completed Part 1 of Form DS-260 (Immigrant Visa Electronic Application) if you are consular processing abroad
- Paying the immigrant visa fee to the Department of State
- Having Form I-824 (Application for Action on an Approved Application or Petition) filed on your behalf
Any single one of these actions, taken within the one-year window, is enough. The clock starts on the date the visa first becomes available for your category and country. If you miss the deadline, USCIS may excuse the delay for extraordinary circumstances not created by your own action or inaction, but the exception is not automatic and must be documented.
If the Calculation Comes Out at 21 or Older
If your CSPA age is 21 or older, the petition automatically converts to the appropriate adult preference category and keeps its original priority date. In practice, an F2A child usually gets reclassified to F2B (unmarried son or daughter 21 or older of a permanent resident). Derivative children of employment-based petitions shift to the appropriate family-based category.
Keeping the original priority date matters, because it preserves your place in line rather than sending you to the back of a new queue. Even so, the adult category almost always has a longer wait, so aging out generally means years of additional waiting.
One condition runs through every category: the child must remain unmarried. Marriage at any point ends child classification, and a later divorce after turning 21 does not restore it.