Inside every RDT&E appropriation, money is sorted into budget activities: bands that describe how mature the work is. BA 1 is a research paper. BA 7 is a fielded system getting an upgrade. The band tells you what the program is allowed to do with the money, and it is the single fastest way to read a program’s real stage regardless of what its briefing slides claim.

The numbering runs in two notations that mean the same thing: “BA 4” and “6.4” are the same band.

The bands

The newer bands

Created to let software move at software speed rather than through the milestone system.

Reading the bands

A program moving from 6.3 to 6.4 is a real event: it means prototypes are expected. A program parked in 6.7 for a decade is sustaining, not innovating. A program that appears directly in 6.8 skipped the traditional maturity ladder on purpose.

Related: appropriations sit above this layer, the hierarchy shows the whole chain, and JCIDS explains how the requirement that justifies the band gets written.