The investor, the investor's spouse, and unmarried children under twenty-one at the relevant time. They receive conditional permanent residence together. A child who turns twenty-one during the process may be protected in part by the Child Status Protection Act, which requires its own analysis.
Derivatives get residence, and one of them may be running out of time
This is the route where the family outcome is strongest and the age question is sharpest. Derivatives receive conditional permanent residence alongside the investor, which means work authorization without any dependant restriction and a path to removing conditions with the family. But a child who reaches twenty-one before the relevant date can fall out of the petition entirely. The Child Status Protection Act allows certain periods to be subtracted from a child's age in defined circumstances, and whether it helps a particular child depends on filing dates, priority dates and visa availability, which for some countries of birth includes waiting for a date to become current in the Visa Bulletin. A family with a child in their late teens should have that calculation done before choosing this route, not after filing.
Hypothetical example: an occupational-safety equipment investor has a child close to twenty-one. The household must decide whether the calculated age and availability timeline fit the case, using civil records, filing facts, availability information, passports, and status history. Record each person’s activity and deadline separately, then sequence admissions, employment, and school steps around those facts. The avoidable problem is that a general claim that children are included ignores the relevant calculation. Do not proceed until everyone has a plan matching their circumstances.