For Sharon Goldfarb, a nurse educator in California, crisis care is second nature: She worked at a Harlem H.I.V. clinic during the AIDS epidemic, at ground zero after Sept. 11 and in New Orleans after Hurricane Katrina. When the coronavirus outbreak began to spread, she was ready to prepare her 85 nursing students for front-line care, if necessary.

Then the calls came from local hospitals: They no longer wanted nursing students to come for clinical rotations, primarily because of public health advisories on limiting the spread of the virus. Not only would her students be unable to help — most would not be able to graduate on time.

The United States is facing a nursing shortfall, and California will be especially hard hit; the state’s vacancy rate for registered nurses is now above 4 percent. The coronavirus will place a tremendous strain on already understaffed hospitals. Yet a growing number of hospitals are discontinuing clinical rotations for the state’s nursing students. The California Board of Registered Nursing requires that 75 percent of a nursing student’s clinical education be completed with patient contact during hospital rotations. Dr. Goldfarb, dean of health sciences at College of Marin, said that if the state did not change that requirement or encourage hospitals to find clinical roles for nursing students, there would be few nursing students graduating in the coming months.

“They’re trying to marshal the resources they have as wisely as they can,” Dr. Goldfarb said of the nursing schools’ clinical partners. “They’re working with limited resources, in people and supplies.” Still, she added, “We’re looking at 14,000 nursing students not graduating in the time of most dire need I’ve seen in my years as a professional nurse. It’s incredibly shortsighted.”