When it comes to the details of the impending $1.2 trillion cut to their budgets, agency officials often find themselves unable to explain just how those cuts would affect the myriad programs on the ground, offering instead a unified message: talk to the Office of Management and Budget (OMB).

Not that the OMB, which has the task of making sure that President Obama’s vision is implemented throughout federal agencies, can always offer more details. When asked why federal agencies have been told not to discuss sequester details, OMB press officers told National Journal to review Deputy Director Jeffrey Zients’s July memo to agencies, telling them to continue normal spending. The OMB also pointed to a 394-page report in September that estimates by how much federal programs would have to be cut in order to meet the $1.2 trillion goal.

The FAA, for example, could take a $1 billion hit; however, the agency remains quiet. “It’s a little scary because I don’t think the agencies know. Can the FAA wall off air-traffic control? It’s all up to the OMB,” said Jane Calderwood, vice president of federal affairs for the Airports Council International.

Contrast this to the transparency expressed last year during the partial FAA shutdown. The agency freely explained that $2.5 billion in contracting money would be ‘held hostage’ by a partial FAA shutdown and 4,000 employees would be furloughed. The agency provided detailed lists of the projects and offices that would be most affected by the shutdown. Transportation Secretary Ray LaHood took over a White House press conference to beg Congress not to let it happen.

There is a big difference between then and now. One could argue that the DOT tactics did not work the last time around. Congress let the FAA close anyway, almost egged on by the administration’s outrage, and it cost the Treasury millions in uncollected airline tax fees.

Now, the only thing that has been made public is the OMB’s analysis. While those numbers are a starting place, they do not give a full picture of how the cuts will work on the ground. For example, $2.5 billion would come from the National Institutes of Health. But that does not give any indication of which research projects, grant programs, and labs will be cut – or by how much. On top of this, agencies and the OMB can shuffle around the cuts to hit programs they think are inefficient, and protect those with Obama administration approval.

Should Congress fail to head off the sequester, final decisions on the cuts would be made between the OMB and congressional appropriators, says Dan Mendelson, an associate director for health at the OMB during the Clinton administration.

“Ultimately it will be like a mini-negotiated round of appropriations with the Congress,” Mendelson said. "And if you want to do some big deficit-reduction bill down the road, you have to make sure you aren’t angering the very people you need as allies.”