Gilberto Cota studied medicine in Mexicali, Mexico, but never practiced medicine because he couldn't get into one of his home country's few residency programs. After moving to Southern California several years ago, Mr. Cota resigned himself to working as a diabetes counselor. His Mexican medical license wasn't valid in the U.S.

Today, Mr. Cota is on the verge of practicing medicine, thanks to a pilot program that taps into the surplus of medical-school graduates in Latin America to address the chronic shortage of U.S. doctors who speak Spanish. Amid a record influx of Latin American immigrants, clinics and hospitals across the country are struggling with Spanish-speaking patients.

Mr. Cota, 33 years old, is on his way to becoming a licensed U.S. physician. He receives a $21,000 stipend from University of California at Los Angeles to take courses that are preparing him for U.S. medical board exams. Mr. Cota recently interviewed at Riverside County Regional Medical Center in Moreno Valley, Calif. Some two-thirds of its patients are Hispanic, and many don't speak English. Yet only eight of the 27 resident family physicians there speak Spanish.

The result is poor communication that can cost millions of dollars annually in unnecessary tests, emergency-room visits and inaccurate or delayed diagnoses. Lack of understanding leads to confusion about medication dosage and side effects, noncompliance with doctors' instructions and a lower likelihood of follow-up care.

"To provide safe and quality care, a physician has to understand the patient," says Patrick Dowling, a professor of family medicine at the David Geffen School of Medicine at UCLA.

Hispanics constitute 14% of the nation's 300 million people. But only 5% of all physicians practicing in the United States are Hispanic.

The Pew Hispanic Center, a nonpartisan research group, reported recently that fewer than one in four Latino immigrants reports being able to speak English very well.

In California, where 33% of the population is Hispanic, only 4% of physicians are Latino. Confronted with this reality, Dr. Dowling and fellow physician Michelle Bholat designed a 14-month program that qualifies graduates from Latin American countries to enter family-medicine residencies at teaching hospitals in California.

Before starting the program, many of the participants had been working in the U.S. as X-ray technicians, nursing assistants or as health-care volunteers. A program that prepares them to work as physicians in the U.S. is "an obvious solution," Dr. Bholat says.

The graduates receive prep courses for U.S. medical licensing exams, observership training at a UCLA hospital and support in their application for a residency program. On completing their residency, participants commit to spending at least three years in a "medically underserved area," in a large city or rural community.

Currently, 14 Latin American medical graduates are enrolled in different stages of the UCLA program, at the cost of about $48,000 apiece. The program, funded entirely by private foundations, is completing its first full year in February. Drs. Dowling and Bholat are currently seeking funds to expand enrollment.

Down the road, the two doctors plan to replicate the program at other University of California campuses, as well as introduce it to other states grappling to serve Spanish-speaking patients. Many states have burgeoning Hispanic populations. In North Carolina, the Hispanic population has jumped to more than 500,000 from 76,000 in 1990, according to the Census Bureau. Midwestern states like Iowa and Wisconsin also have seen steep increases.

Texas, where 35% of the population is Hispanic, is already eyeing the UCLA pilot. "This is a socially-responsible program that we need to replicate in Texas," says Carlos Jaén, chairman of the Department of Family & Community Medicine at the University of Texas Health Sciences Center at San Antonio.

Dr. Jaén says that he has witnessed "multiple occasions" when miscommunication has resulted in "dangerous situations." For example, the word "once" is spelled the same as the Spanish word for eleven. When a prescription states that a medication be taken "once a day," some Spanish-speaking patients have interpreted it as 11 pills daily. For heart medication, this dose could be toxic and cause death.

There is little research about the link between language barriers and medical errors. In a survey conducted in 2003 by the California Academy of Family Physicians, nearly half of all doctors said they were familiar with incidents in which quality of care had been compromised by language barriers. One doctor reported that a patient with shortness of breath was believed to be having an anxiety attack. In fact, he was suffering from a diabetes complication called diabetic ketoacidosis that can cause a coma.

In another reported case, a patient told a physician he had a "mass" in his chest, suggesting a tumor. In fact, the patient had a leak from a previously diagnosed abdominal aortic aneurysm, a vascular condition. The patient's poor English and misunderstanding of the previous doctor delayed care for a condition that can be fatal.

In 2000, 11.9 million U.S. residents were members of a "linguistically isolated" household, in which no person age 14 or over speaks English at least very well, compared with 7.7 million in 1990, according to the Census Bureau. In that decade, there was a 53% surge in the number of U.S. residents whose English proficiency is limited. "Unfortunately, cases in which language barriers cause compromised quality of care and preventable medical errors may become increasingly common," says Glenn Flores, professor and director of general pediatrics at the University of Texas Southwestern Medical Center in Dallas.

Meanwhile, Latin American countries produce more medical school graduates than their hospitals can accommodate for residency training. In Mexico, about 12,000 students complete medical school each year but hospitals only offer 4,300 residency slots. The UCLA program is designed to tap into that oversupply.

Blanca Campos, who couldn't secure a spot in a residency program in Costa Rica, recently passed her medical boards and is applying for a position as a family-practice resident at Los Angeles hospitals that cater to many immigrants. "If they see doctors who understand their language and culture, these patients are more open about their health issues," she says.

Asma Jafri, the physician who supervises the family medicine residency program in Riverside, says that the majority of patient complaints at the county hospital concern miscommunication. Aside from language fluency, Latin American doctors are able to grasp cultural nuances and native medical practices, such as use of herbal remedies, that may be relevant to a patient's case.

"The schedules of physicians fluent in Spanish are always full as opposed to the doctors who only speak English," Dr. Jafri says.