FY2025 obligations by the NAICS code on the award
21% of the $27.0B obligated under R499 in FY2025 went to awards coded NAICS 541330.
FY2025 federal contract obligations, USAspending.gov
PSC R499 sits at the bottom of the R4 professional support series as its residual bucket. The PSC Manual gives R499 no includes or excludes list at all, because its job is to absorb professional support requirements that do not match R405 operations research, R408 program management, R425 engineering and technical support, R423 intelligence, or any of the two dozen other named R4 codes. Residual status has not kept it small: $27.0 billion moved under R499 in FY2025, more than any federal service code except R425 itself.
Who gets paid under R499
The spread is unusually wide for a single code. Engineering Services carries $5.7B, management consulting under 541611 takes $3.8 billion, 541990 takes $3.4 billion, and computer systems design 541512 adds $2.3 billion. Aircraft manufacturing appears fifth at $1.67 billion, which is the tell that R499 also rides along on original-equipment sustainment work, not just pure advisory contracts.
One line on the two code systems
A PSC answers "what did the government buy," a NAICS code answers "what industry is the work in," and R499 is proof that the first answer is sometimes just "professional support, unspecified."
Treat R499 as a filter, never a search term. Because the code carries no subject matter of its own, a keyword-free R499 query returns noise; pair it with an awarding agency and a NAICS code before you read a single notice.
PSC R499 FAQ
What does PSC R499 cover?
Professional support services that do not fit any named R4 code. The manual defines it only as Support (Professional): Other, so its scope is defined by exclusion, not by a description.
What NAICS codes win R499 work?
In FY2025, Engineering Services (541330) led at $5.7 billion, followed by 541611 at $3.8 billion and 541990 at $3.4 billion. No single industry dominates, which is what you would expect from a residual code.
Should I search R499 or R425 for engineering support work?
Start with R425, which the manual defines as systems engineering and technical assistance supporting a program office. R499 is where similar work lands when the contracting officer decides the requirement blends disciplines. Watching only one of the two leaves money on the table.
Why is aircraft manufacturing among the top R499 NAICS codes?
An award carries the NAICS code assigned to the whole contract, not to each task. When an aircraft manufacturer sells program support alongside a platform, the award can show a manufacturing NAICS against a professional-services PSC.