It is customary in higher education to dismiss rankings as misleading and arbitrary, quantifying things that don’t much matter about colleges and universities.

But one list of undisputed significance is compiled each year by the National Science Foundation: the top institutions ranked by total research spending. Such money supports laboratories, attracts top faculty and graduate students, and gives many undergraduates a chance to learn through experimentation.

On this list, Johns Hopkins University in Baltimore is the perennial and unchallenged national leader. New data from the NSF show that Hopkins spent $2.1 billion on research and development in the fiscal year that ended in 2012. The University of Michigan ranked second, spending $1.3 billion.

The Hopkins figure includes $1.1 billion spent at the Applied Physics Laboratory in Howard County, as well as major sums spent for biomedical research at the university’s medical center.

Six other schools joined Hopkins and Michigan in fiscal 2012 in the billion-dollar club. They were, in order, the University of Wisconsin, the University of Washington, the University of California at San Diego, the University of California at San Francisco, Duke University and UCLA.

Here are other schools in Maryland, Virginia and the District that placed in the top 200 in R&D spending:

University of Maryland at College Park ($502 million, 37th)

Virginia Tech ($454 million, 40th)

●University of Maryland at Baltimore ($433 million, 47th)

●University of Virginia ($383 million, 59th)

●Virginia Commonwealth University ($201 million, 101st)

●George Washington University ($196 million, 103rd)

●Georgetown University ($180 million, 108th)

●Uniformed Services University of the Health Sciences ($151 million, 121st)

●Old Dominion University ($105 million, 145th)

George Mason University ($90 million, 154th)

●University of Maryland, Baltimore County ($75 million, 167th)

●College of William and Mary ($56 million, 195th)

Among other universities in the District, Howard ranked 208th, American 209th, Catholic 253rd, Gallaudet 371st and the University of the District of Columbia 424th.

Notably, some of the region’s universities were able to grow their R&D spending in a year when it was stagnant or declining at many institutions. Among them were University of Maryland at Baltimore, up $24 million; Georgetown, up $10 million, U-Md., up $7 million; Salisbury University, up $5 million to $6.9 million; and Morgan State University, up $5 million to $18 million.

The largest funding source for university R&D is the federal government. Still unknown is exactly how much this year’s federal budget cuts, known as the sequester, reduced research spending at universities. But many university presidents say the impact was large.

It’s worth pointing out that the top tier of the list is dominated by universities with medical schools, which receive major funding from the National Institutes of Health and other sources. If such universities were excluded, U-Md. and Virginia Tech would both rank in the top 10 nationally.

Here’s another interesting exercise. U-Md. in Baltimore does have a medical school. If it were combined with College Park — a notion sometimes floated — the total annual research spending for the merged institution, more than $930 million, would place in the top 10 nationally.