NIH is operating under an FY07 Continuing Resolution (CR), which applies the terms of NIH's FY06 appropriation. The FY06 Appropriation Act (PL 109-149) restricts the amount of direct salary to the "Executive Level 1" level, as determined by the federal executive pay scale.
Effective as of January 1, 2009, the salary limitation for Executive Level 1 is $196,700.
Despite the fact that NIH is operating under the CR, the $186,600 level represents official NIH policy.
The link can be found at: http://grants.nih.gov/grants/guide/notice-files/NOT-OD-07-033.html.