One law says the NSF should be $18.9 billion next year. The budget request says $3.96 billion.

The finding, in one paragraph: the National Science Foundation — funder of about a quarter of all federally supported basic research at American universities — currently has three official sizes, issued by the same government, that differ by a factor of 4.8.▸ A statute on the books authorizes $18.9 billion for fiscal 2027. The most recent appropriation, signed in January after Congress explicitly declined to enact a 55 percent cut, is $8.75 billion. And the budget request delivered to Congress in April asks for $3.96 billion — the same halving Congress just rejected, resubmitted with the same structure. While those three numbers contend, a fourth process has been deciding the question on the ground: 1,752 grants already awarded were terminated mid-stream, and the workforce that runs the agency shrank 32.5 percent in thirteen months.

Four documents, read directly.▸ The authorization is the CHIPS and Science Act (P.L. 117-167, August 2022), whose NSF section authorizes, verbatim, "$18,919,180,000 for fiscal year 2027" — the last step of a five-year ramp from $11.9 billion. The request is NSF's FY2027 Budget Request to Congress (April 3, 2026), whose own tables carry the FY2026 enacted figure of $8,750.00 million. The workforce count is GAO's audited federal-workforce ledger (June 17, 2026): NSF from 1,719 employees in December 2024 to 1,161 in January 2026 — the largest proportional decline of any science agency measured. The termination tallies and directorate-level analyses are from the Computing Research Association's and American Astronomical Society's readings of the request, cross-checked against the request's own tables.

The request's internals show where a halving lands.▸ The research account falls to $3.41 billion — a cut of roughly 52 percent from the FY2026 level. Per the analyses of the request's directorate tables: Mathematical and Physical Sciences down about 67 percent, STEM Education down about 64 percent, Geosciences down 58 percent, and the Social, Behavioral and Economic Sciences directorate terminated as a unit. The Graduate Research Fellowship Program — the program that funded the graduate work of dozens of eventual Nobel laureates — is budgeted at $246.5 million. The one growth item is $900 million in proposed mandatory funding for an Antarctic icebreaking vessel.

Authorizations are promises, not checks, and the NSF's have been underfunded since the ramp began.▸ What changed this cycle is the direction of the miss:

Through FY2026 the appropriations ran at roughly half the authorized level — a familiar Washington gap.▸ The FY2027 request breaks the pattern: it proposes 21 percent of the statutory figure, for the fiscal year in which the statute's ramp reaches its peak.

The constitutional choreography here is unusually legible.▸ Congress spoke twice: once in 2022, authorizing growth to $18.9 billion by bipartisan statute; again in January 2026, rejecting the proposed 55 percent cut and appropriating $8.75 billion. The executive's April request re-proposes what was just declined — its prerogative, but on the record as a second ask for a number Congress already refused. The third mechanism is the one that operates without either: during fiscal 2026, under the $8.75 billion appropriation Congress did enact, 1,752 already-awarded grants worth about $1.4 billion were terminated — including 839 grants worth $888 million in STEM education alone — and the agency's staff fell by a third, per GAO's audited count. Whatever number Congress writes, the operating scale of the agency has already been moved most of the way toward the requested one, by administrative action the appropriations process never voted on.

The FY2027 appropriations cycle is live now — the House and Senate CJS subcommittees mark up this summer against the April request, and January's $8.75 billion suggests where Congress's floor has been.▸ The structural questions ride with it: whether terminated grants and departed staff can be restored by an appropriation, whether the authorization's final-year figure retains any force, and whether the FY2028 request — the first written after the CHIPS ramp expires — abandons the statute's baseline entirely. Each is checkable in documents: the appropriations bills, NSF's termination notices, and the next GAO workforce update.

The authorization figures and the FY2027 request/enacted figures are read directly from the statute and NSF's budget documents. The grant-termination counts and directorate percentages are analyses of the request and NSF award data by the research-community organizations cited; GAO's workforce figures are audited agency-reported counts.