The program describes a joining spouse and unmarried children under 21, each of whom must be considered in the initial application. Being listed is not enough on its own: every person still needs to be eligible for lawful permanent residence and admissible. Check each child's age and marital status against that category before the household commits.
Write the household list before pricing
Start with names, dates of birth, and marital status rather than a total. A four-person list produces one budget; a five-person list, if an older child qualifies, produces another that is a million dollars larger. Confirm with a qualified adviser which relatives fit the described category and which do not, then price only the confirmed list.
Rework the figure if the household composition changes before filing. Two facts should sit above the household list before any pricing is done. The payment runs from the applicant to the U.S.
government and buys neither a classification nor relief from any ground of inadmissibility, so it cannot solve a problem in anyone's record. And each person included is assessed individually, which means the family's outcome depends on the weakest record in it rather than on the strongest. Screen every adult's history — refusals, overstays, charges, inconsistent travel records — before the list is priced rather than after.
Hypothetical example: a household of four prices the application carefully and only afterwards discovers a visa refusal in one adult's history from many years earlier, which is exactly the kind of fact that should have shaped the plan rather than interrupted it.