When Afrika Gupton-Jones was on bed rest in the hospital, after developing high blood pressure at 28 weeks of pregnancy, her husband was with her day and night. Yet the nurses often assumed that he was her brother, and that she was a single mother. When the doctors and nurses gave her medications or took her blood, she said, they gave her minimal explanation.

“It’s like they didn’t trust me with my own bodily decisions,” she said.

In the United States, people who have more money generally receive better health care: More expensive insurance plans usually cover more doctors, and well-off patients can afford the increasingly high out-of-pocket costs that come with medical care. But despite being upper-middle-class and privately insured, Ms. Gupton-Jones and her husband felt they were treated insensitively. Her career in marketing didn’t make a difference in how doctors and nurses saw them, she said, nor did his doctoral degree.

Earning more and being well educated generally doesn’t protect Black mothers during childbirth the same way it protects white mothers. A new study of a decade of births in California, published this year, found that the richest Black mothers and their babies were twice as likely to die from childbirth as the richest white mothers and their babies.

Missing from mortality statistics are the many stories of mistreatment and negative experiences. In interviews with Black women who responded to a request from The New York Times to share their birth stories, they described having their pain dismissed, concerns ignored and plans disregarded while giving birth. They recalled walking a fine line between speaking up for themselves but feeling nervous to push too hard.

Numerous studies suggest that racism, and how it affects Black women’s health throughout their lives, is a primary driver. It starts long before women become pregnant, researchers say. It happens across health care settings, with research showing that even if medical staff is empathetic overall, just one such interaction can have a big effect. It continues through childbirth, when discrimination, unconscious or not, affects Black mothers’ hospital care.

“These long-term issues of disparities in maternal outcomes can’t be boiled down to class,” said Tyan Parker Dominguez, who studies race and birth outcomes at the University of Southern California School of Social Work. “Racism doesn’t just operate along economic lines, because even when you control for that, it’s still a factor.”

Ms. Gupton-Jones’s son Sidney, now 8, was born at 30 weeks, and stayed in the neonatal intensive care unit for six weeks. It was filled with families of color, she said, while the health care professionals at the suburban Ohio hospital were white. They took good care of Sidney, she said, but she and her husband felt they were treated dismissively.

Though she was comfortable advocating for herself in her career, she said, she and her husband said nothing at the hospital, because they didn’t want to create conflict with the people taking care of Sidney. “You had to have a blind trust in the overnight shift that they were taking care of your child appropriately,” she said, “so you didn’t want to rock the boat.”

Racism can have long-term effects on health

Studies show that high levels of income and education generally lead to better birth outcomes, like lower rates of C-sections, preterm births and infant mortality — except when the mother is Black.

One reason is that many Black women with more resources probably ascended into their class recently, said Professor Parker Dominguez. Her research has found that the resources that women had growing up have a greater effect on their reproductive health than the socioeconomic status they’ve achieved as adults.

“They’re likely to have lived in disadvantage, which doesn’t get undone just because you reach 30 years old and you’re reaching $100,000 in income,” she said.

There is also evidence, in her work and that of others, that experiencing racism has long-term effects on health. It can increase incidences of underlying conditions like hypertension and diabetes, and affect birth outcomes. These effects can be passed down through generations.

“It’s been maybe a generation or two since we’ve had opportunities for African Americans to move en masse into the middle class,” Professor Parker Dominguez said.

Studies find that Black women who plan to deliver without an epidural are more likely to be pressured into using one. C-section rates are lower for white women with advanced degrees, but not for highly educated Black or Hispanic women. When Black women have C-sections, they are twice as likely as white women to receive general anesthesia, which makes them unconscious for their child’s birth.

New mothers who are Black are significantly more likely to be tested for drugs than white mothers, even though white mothers are more likely to test positive, a new study conducted in Pennsylvania found.

Black women are more likely to be reported to child welfare services after giving birth. In qualitative studies, they have described health care workers who have assumed they are single or have multiple children or low incomes, whether or not those things are true.

“Regardless of socioeconomic status, when a Black mother or birthing person presents to a health care system, they are starting out being up against racial stereotypes,” said Jaime Slaughter-Acey, an epidemiologist at the University of Minnesota who studies racism in health care.

In pain, but afraid to speak up

Lia Gardley, 32, had hoped to deliver her son, Jaxson, without an epidural. A construction manager, she thought that if she could make it past seven centimeters dilation, the point at which she had learned the pain peaks, she could make it all the way. Her repeated requests to the nurse to check how far she was dilated, though, were denied.

“She kept saying, ‘No, if you’re having so much trouble, you should just get the epidural,’” Ms. Gardley said.

Exhausted, and unsure how much labor she had left, she agreed to the epidural. Shortly after, a nurse checked her dilation, only to find she’d already made it past seven centimeters.

“It still bothers me when I think about it, because I had such intention and determination, and all I had needed them to do was give me all the information so I could make my informed decision,” Ms. Gardley said.

Others described being subject to stereotypes. One woman said a pediatrician assumed her baby was on Medicaid. Another described a nurse referring to her domestic partner, now husband, as a “baby daddy.” A third was accused of inappropriately seeking opioids when she repeatedly returned to the hospital after delivery because she was experiencing intense headaches and dangerously high blood pressure.

“The nurse said, ‘What is it you want? This is your third time here, what do you want, Dilaudid?’” a mother and physician in Maryland said. “I just said, ‘No thank you, I guess it’s time for me to go,’ and I didn’t go back, because clearly the nurse thought I was drug seeking. And that didn’t feel good at all.”

The physician, who did not want to use her name because of her professional connections in health care, said she and her husband decided not to have another child, in large part because of her experience after the delivery.

“I think that historically, Black people’s pain has been dismissed and under-treated,” she said. “There are all these myths. I don’t know that there’s anything sinister — just like with many things with racism and disparities in health care, a lot of it is unconscious, and your own assumptions clouding your judgment.”

Many Black mothers described walking a tightrope: wanting to make providers aware of their knowledge or even their expertise as health care workers themselves, but also to avoid being labeled difficult.

Sade Meeks worked in a neonatal intensive care unit while she was pregnant with her daughter Leilani in November 2020, two months before her due date. Ms. Meeks had a difficult, emergency C-section; she recalled fading in and out of consciousness while she was wheeled into the operating room. She was surprised and concerned when the hospital said she was ready for discharge just three days later.

“I could barely stand,” she said. “I was in so much pain but I didn’t want to make a scene. If I started yelling or making demands, I know I’d be labeled the ‘angry Black woman.’ They said things to me like, ‘You’re a woman, you’re strong, other women have been through worse.’”

In her NICU work, Ms. Meeks had seen how the hospital was more likely to involve child welfare services with Black families, a trend that holds true nationwide. She feared that pushing back too hard could have that consequence, so she reluctantly went home.

But the next day, still in terrible pain, Ms. Meeks went to another hospital’s emergency room and was diagnosed with a serious infection. She was admitted, and spent weeks there recovering while her daughter was across town in another hospital’s NICU. She tried shipping breast milk to Leilani, but the logistics proved impossible.

“It was traumatic, and I felt like I’d failed not only myself but my child,” Ms. Meeks said. “I wish I’d been more assertive with my concerns, but they kept brushing them off.”

‘We can’t change what we don’t name’

Dr. Donna Adams-Pickett, a practicing obstetrician in Georgia, said she treats all her Black patients’ pregnancies as high-risk ones because of the well-documented poor outcomes.

“There are often excuses for our complaints and our concerns, which are consistently minimized,” she said. “I find myself often having to serve more as an advocate than as a physician.”

Even her presence as a Black physician may help protect her patients: Studies find that Black newborns delivered by Black doctors have better outcomes.

But she also finds that bias extends to her as a Black female obstetrician. Dr. Adams-Pickett, who has practiced for decades and delivers hundreds of babies annually, described instances in which white doctors involved in deliveries dismissed her expertise. Once, she said, another doctor questioned her order for an emergency C-section, and she had to point to the fetal tracing monitor and show him the blood between the patient’s legs to convince him.

“It bothered me that I had to go through all these steps, and lose valuable time, to prove to him that my patient needed emergent surgery,” she said.

The women in these stories survived and so did their babies, so for most of them, their negative experiences were not categorized as poor outcomes. Yet to combat racism in hospital care, said Dr. Karen A. Scott, an obstetrician, it has to be tracked. At her organization, Birthing Cultural Rigor, she developed a survey to measure racism during childbirth.

It asks patients about mistreatment, and concerns like whether mothers felt they had open communication with and empathy from health care providers, and how their partners or others were treated at the hospital. It surfaces issues, like Black husbands who are policed in hospital hallways, that would not otherwise be noted.

“When we just look at outcomes, we minimize what hurts Black birthing people,” she said. “We can’t change what we don’t name, what we don’t measure and monitor.”

More than 20 years after scientists first released a draft sequence of the human genome, the book of life has been given a long-overdue rewrite.

A more accurate and inclusive edition of our genetic code was published on Wednesday, marking a major step toward a deeper understanding of human biology and personalized medicine for people from a wide range of racial and ethnic backgrounds.

Unlike the previous reference — which was largely based on the DNA of one mixed-race man from Buffalo, with inputs from a few dozen other individuals, mostly of European descent — the new “pangenome” incorporates near-complete genetic sequences from 47 men and women of diverse origins, including African Americans, Caribbean Islanders, East Asians, West Africans and South Americans.

The revamped genome map represents a crucial tool for scientists and clinicians hoping to identify genetic variations associated with disease. It also promises to deliver treatments that can benefit all people, regardless of their race, ethnicity or ancestry, researchers said.

“It’s been long needed — and they’ve done a very good job,” said Ewan Birney, a geneticist and deputy director general of the European Molecular Biology Laboratory, who was not involved in the effort. “This will improve our fine-grained understanding of variation, and then that research will open new opportunities toward clinical applications.”

Powered by the latest in DNA sequencing technology, the pangenome collates all 47 unique genomes into a single resource, providing the most detailed picture yet of the code that powers our cells. Gaps in the earlier reference are now filled, with nearly 120 million previously missing DNA letters added to the three-billion-letter-long code.

Gone is the idea of a totemic strand of DNA that extends six feet when uncoiled and stretched out in a straight line. Now, the rebooted reference resembles a corn maze, with alternative paths and side trails that allow scientists to explore a broader range of the genetic diversity found in people the world over.

Dr. Eric Green, director of the National Human Genome Research Institute, the government agency that funded the work, likens the pangenome to a new kind of bodywork manual for automotive repair shops. Whereas before, every mechanic only had the design specs for one kind of car, now there is a master plan that covers different makes and models.

“We’ve gone from having one really nice blueprint of the Chevy to now having blueprints of 47 representative cars from each of 47 different manufacturers,” he said.

Knowing what to do with this Kelley Blue Book of genomics will involve a steep learning curve. New analytical tools are needed. Coordinate systems must be redefined. Widespread adoption will take time.

“Making this easy to be used by the community is work to be done,” said Heidi Rehm, chief genomics officer at Massachusetts General Hospital in Boston, who was not involved in the project.

But in due course, experts said, the pangenome will revolutionize the field of genomic medicine.

“We’re going to have the benefit of actually understanding ourselves as a species much, much better,” said Evan Eichler, a genome scientist at the University of Washington. Dr. Eichler was among more than 100 scientists and bioethicists who described the new pangenome reference in the journal Nature.

The architects of the project are continuing to add more population groups, with the goal of including at least 350 high-quality genomes that encompass the bulk of global human diversity.

“We want to represent all the branches of the human tree,” said Ira Hall, a geneticist who leads the Yale Center for Genomic Health.

Some of the new genomes will come from New Yorkers who previously participated in a research program at the Mount Sinai Health System. If their preliminary DNA data seems to reflect certain underrepresented genetic backgrounds, those individuals will be invited to participate in the pangenome project.

Some gaps might never get plugged in the publicly available reference, though — by design.

Previous attempts to capture human genetic diversity often extracted sequence data from marginalized populations without regard for their needs and preferences. Informed by those ethical missteps, pangenome coordinators are now collaborating with Indigenous groups to develop formal policies around data ownership.

“We are still grappling with the issue of native and tribal sovereignty,” said Barbara Koenig, a bioethicist at the University of California, San Francisco, who was involved in the project.

In Australia, researchers are incorporating DNA sequences from various Aboriginal peoples into a similar depository that will be combined with the open-source pangenome, but then kept behind a firewall. According to Hardip Patel of Australia’s National Centre for Indigenous Genomics in Canberra, the scientists next plan to consult with community leaders about if or how to make the data accessible through request.

Some Indigenous advocates want to see the pangenome project go further. Keolu Fox, a genomics scientist at the University of California, San Diego, who is Native Hawaiian has suggested training the next generation of Indigenous scientists to have greater agency over the genomic data.

“It’s finally time that we decentralize power and control and redistribute that among the communities themselves,” Dr. Fox said.

Ayla Wing’s middle school students don’t always know what to make of their 26-year-old teacher’s hearing aids. The most common response she hears: “Oh, my grandma has them, too.”

But grandma’s hearing aids were never like this: Bluetooth-enabled and connected to her phone, they allow Ms. Wing to toggle with one touch between custom settings. She can shut out the world during a screeching subway ride, hear her friends in noisy bars during a night out and even understand her students better by switching to “mumbly kids.”

A raft of new hearing aids have hit the market in recent years, offering greater appeal to a generation of young adults that some experts say is both developing hearing problems earlier in life and — perhaps paradoxically — becoming more comfortable with an expensive piece of technology pumping sound into their ears.

Some of the new models, including Ms. Wing’s, are made by traditional prescription brands, which usually require a visit to a specialist. But the Food and Drug Administration opened up the market last year when it allowed the sale of hearing aids over the counter. In response, brand names like Sony and Jabra began releasing their own products, adding to the new wave of designs and features that appeal to young consumers.

“These new hearing aids are sexy,” said Pete Bilzerian, a 25-year-old in Richmond, Va., who has worn the devices since he was 7. He describes his early models as distinctly unsexy: “big, funky, tan-colored hearing aids with the molding that goes all around the ear.” But increasingly, those have given way to sleeker, smaller models with more technological capabilities.

Nowadays, he said, no one seems to notice the electronics in his ear. “If it ever does come up as a topic, I just brush it off and say, ‘Hey, I got these very expensive AirPods.’”

More people in Mr. Bilzerian’s age group might need the equivalent of expensive AirPods, experts say. By the time they turn 30, about a fifth of Americans today have had their hearing damaged by noise, the Centers for Disease Control and Prevention recently estimated. This number adds to the already substantial population of young people with hearing loss tied to genetics or medical conditions.

The exact number of young adults who need or use hearing aids is difficult to pinpoint, but both device manufacturers and medical experts say that population is growing. The leading prescription aid manufacturer, Phonak, says the number of Americans between the ages of 22 and 54 who have been fitted with the company’s hearing aids increased by 14 percent more than the increase for users of all other ages between 2017 and 2021.

“Anecdotally, we have seen more young people over the past decade pursuing hearing protection. This seems to be much more mainstream, which is great,” said Dr. Catherine V. Palmer, director of Audiology and Hearing Aids at the University of Pittsburgh Medical Center and Children’s Hospital.

Experts say there are several reasons that hearing aids are closing the generation gap. Attitudes have changed as technology has advanced, leading more young people to be willing to give them a try. And a growing number of 20-somethings may need them as they navigate an increasingly noise-soaked world; more than a billion young people worldwide risk noise-induced hearing loss, according to the World Health Organization.

But there are still significant barriers: Hearing aids are expensive — especially for people who lack good medical insurance — with most costing $1,000 or more. And the options can be confusing and difficult to navigate; many models still have to be prescribed by an audiologist. And while the stigma might be fading, it has not entirely vanished.

Data collected in 1989 by MarkeTrak, a consumer research organization that is part of the Hearing Industries of America, suggested that people who wore hearing aids “were perceived to be less competent, less attractive, less youthful and more disabled.” Today, though, the organization said in a recent report, hearing aid users “rarely or never feel embarrassed or rejected.”

While the emergence of over-the-counter hearing aids has provided new options, it has also made diving into the market more complicated. There are dozens of brands to choose from, ranging from small, in-ear pods to those that use long metallic arcs around the ear. Most new models have Bluetooth streaming capacities. And some of the over-the-counter options can even be ordered online with free shipping.

Blake Cadwell created Soundly, a website that allows users to compare hearing aid brands and prices, after trying to navigate the complex market himself.

“When I started the process, the main thing I experienced was it’s difficult to know where to start and how to start, just figuring out which way was up,” said Mr. Cadwell, 32, who lives in Los Angeles.

Even just getting a diagnosis for hearing loss can be hard. People who are concerned about their hearing might start at an ear, nose and throat specialist, and many are referred to audiologists or hearing clinics, where they face a mix of hearing tests, physical exams or imaging.

Juliann Zhou, a 22-year-old international student at New York University, was motivated to get her ears checked after being disturbed by an intense ringing, which was diagnosed as tinnitus from moderate hearing loss. Still, she has not been sold on hearing aids. An audiologist in the United States recommended them, but her parents and their family doctor in China told her they were “only for old people.”

“I just don’t know if it’s necessary,” she said.

Ms. Zhou says she “probably listened to music too loud,” causing her hearing issues. That’s an increasingly common concern, according to the Hearing Loss Association, which has called noise-induced hearing loss a growing public health crisis.

Though long-term tracking data is not available, the association estimates that 12.5 percent of Americans between the ages of 6 and 19 have hearing loss as a result of listening to loud music, particularly through earbuds at unsafe volumes.

For those who need them, the new wave of over-the-counter aids can be more affordable than many prescription models. That makes them a good first choice for more young people, said Zina Jawadi, 27, who has used hearing aids since she was 4 and attends medical school at the University of California, Los Angeles.

“This is one of the biggest things I’ve seen in a really long time in this space,” she said.

Ms. Wing, the middle school teacher, said she decided to buy her new hearing aids just months before she would turn 26 and lose access to her parents’ health insurance plan. Otherwise, the $4,000 prescription hearing aids would have been unaffordable, she said.

Ms. Wing worried about the durability and effectiveness of over-the-counter aids, compared with her prescription pair, which she expects to last at least five years.

“I wear glasses too, and I can’t just get reading glasses from CVS — I have to get them from the eye doctor,” she said. “It’s the same with my hearing aids.”

Ms. Wing said she had many co-workers in their 40s and 50s who could probably benefit from hearing aids but are worried about negative perceptions. She tries to dispel that.

“I tell everyone that I know that I have hearing aids,” Ms. Wing said, “just so that the stigma is less.”

It’s no surprise that the shortage of primary care doctors — who are critically important to the health of Americans — is getting worse.

They practice in one of medicine’s lowest paid, least glamorous fields. Most are overworked, seeing as many as 30 people a day; figuring out when a sore throat is a strep infection, or managing a patient’s chronic diabetes.

So why are multibillion-dollar corporations, particularly giant health insurers, gobbling up primary care practices? CVS Health, with its sprawling pharmacy business and ownership of the major insurer Aetna, paid roughly $11 billion to buy Oak Street Health, a fast-growing chain of primary care centers that employs doctors in 21 states. And Amazon’s bold purchase of One Medical, another large doctors’ group, for nearly $4 billion, is another such move.

The appeal is simple: Despite their lowly status, primary care doctors oversee vast numbers of patients, who bring business and profits to a hospital system, a health insurer or a pharmacy outfit eyeing expansion.

And there’s an added lure: The growing privatization of Medicare, the federal health insurance program for older Americans, means that more than half its 60 million beneficiaries have signed up for policies with private insurers under the Medicare Advantage program. The federal government is now paying those insurers $400 billion a year.

“That’s the big pot of money everyone is aiming at,” said Erin C. Fuse Brown, director of the Center for Law, Health & Society at Georgia State University, and an author of a New England Journal of Medicine article about corporate investment in primary care. “It’s a one-stop shop for all your health care dollars,” she said.

Many doctors say they are becoming mere employees. “We’ve seen this loss of autonomy,” said Dr. Dan Moore, who recently decided to start his own practice in Henrico, Va., to have more say in caring for his patients. “You don’t become a physician to spend an average of seven minutes with a patient,” he said.

The absorption of doctor practices is part of a vast, accelerating consolidation of medical care, leaving patients in the hands of a shrinking number of giant companies or hospital groups. Many already were the patients’ insurers and controlled the distribution of medicines through ownership of drugstore chains or pharmacy benefit managers. But now, nearly seven in 10 of all doctors are either employed by a hospital or a corporation, according to a recent analysis from the Physicians Advocacy Institute.

The companies say these new arrangements will bring better, more coordinated care for patients, but some experts warn the consolidation will lead to higher prices and systems driven by the quest for profits, not patients’ welfare.

Insurers say their purchase of medical practices is a step toward what is called value-based care, with the insurer and doctor paid a flat fee to care for an individual patient. The fixed payment acts as a financial incentive to keep patients healthy, provide more access to early care and reduce hospital admissions and expensive visits to specialists.

The companies say they favor the fixed fees over the existing system that pays doctors and hospitals for every test and treatment, encouraging doctors to order too many procedures.

Under Medicare Advantage, doctors often share profits with insurers if the doctors take on the financial risk of a patient’s care, earning more if they can save on treatment. Instead of receiving a few hundred dollars for an office visit, primary care doctors can be paid as much as $14,000 a year to manage a single patient.

But experts warn these major acquisitions threaten the personal nature of the doctor-patient relationship, especially if the parent company has the authority to dictate limits on services from the first office visit to extended hospital stays. Once enrolled, these new customers can be steered toward chains of related businesses, like a CVS drugstore or Amazon’s online pharmacy.

UnitedHealth Group is a sprawling example of consolidated services. It owns the major insurer that has nearly 50 million customers in the United States and oversees its ever-expanding subsidiary, Optum, which has bought up networks of doctors and medical sites. Optum can send patients from one of its roughly 70,000 doctors to one of its urgent care or surgery centers.

Senator Elizabeth Warren, Democrat of Massachusetts, is urging the Federal Trade Commission to take a closer look at some of these large deals, which regulators have so far not blocked on antitrust grounds. “I fear that the acquisition of thousands of independent providers by a few massive health care mega-conglomerates could reduce competition on a local or national basis, hurting patients and increasing health care costs,” she wrote to regulators in March.

This consolidation of medical care may also run afoul of state laws that prohibit what is called corporate medicine. Such statutes prevent a company that employs doctors from interfering with patient treatment.

And experts warn of the potential harm to patients, when corporate management seeks to control costs through byzantine systems requiring prior authorization to receive care.

For example, Kaiser Permanente, the giant nonprofit health plan that has exclusive contracts with physician groups, settled a malpractice case for nearly $2.9 million last year with the family of Ken Flach, a former tennis player who contracted pneumonia and died from sepsis after a Kaiser nurse and doctor would not send him for an in-person visit or to the emergency room, despite the urgent pleading of his wife. Kaiser said medical decisions are made by its providers in consultation with their patients and said its “deepest sympathy remains with the Flach family.”

Doctors also chafe at oversight that does not benefit patients. “They are trying to run it like a business, but it’s not a business,” said Dr. Beth Kozak, an internal medicine doctor in Grand Rapids, Mich.

Her doctors’ group has teamed up with Agilon Health, an investor-owned company, to work with Medicare Advantage plans. Dr. Kozak said she has to work longer hours, not to provide better care, but to supply additional diagnoses for patients, which increases federal reimbursements under the Medicare Advantage program. “It’s not because I’m giving better patient care,” she said. “It’s all tied to the billing.”

The corporate consumption of medical care keeps growing. Walgreens Boots Alliance, one of the largest U.S. pharmacy operations, spent $5 billion for a majority stake in VillageMD, a primary care group, and teamed with Cigna to buy another medical group for nearly $9 billion. And short of an outright purchase, UnitedHealth is partnering with Walmart to offer care to older patients.

In promoting the benefits of buying Oak Street clinics to investors, Karen S. Lynch, the chief executive of CVS Health, said primary care doctors lower medical costs. “Primary care drives patient engagement and positive clinical outcomes,” she said.

Many of these companies are building chains of clinics. On a recent tour of an Oak Street clinic in Bushwick, one of 16 centers opened since October 2020 in New York City, patients were typically seen from 8 a.m. to 5 p.m., with a nurse available after hours to field questions.

Ann Greiner, the chief executive of the Primary Care Collaborative, a nonprofit group, defended the recent forays by private companies into this field of health care, saying they are infusing practices with sorely needed funds and may improve access to care for people in underserved areas.

“The salaries of the folks in those arrangements are higher,” she said. “They are providing more comprehensive care in many of those arrangements. They are providing more tech and more team-based care. That’s all investment.”

But these deals also risk shifting the balance from quality treatment to profits, she said.

In recent years, some have invoked the laws banning corporate medicine to challenge these large-scale private operations. Envision Healthcare, a private equity-backed company that employs emergency room doctors, is being sued in California by a unit of the American Academy of Emergency Medicine, a professional group that supports independent practices, accusing it of violating that state’s provisions.

“Envision exercises profound and pervasive direct and indirect control and/or influence over physicians practice of medicine,” according to the lawsuit. The suit maintains that Envision controls the doctors’ billing and establishes medical protocols.

While Envision would not comment on the litigation, it said it “follows an operating structure that is common across the health care sector and widely used by nonprofit, privately held and public groups as well as hospitals and insurers.”

The big insurers find doctors’ groups particularly attractive, although many have reported sizable losses. The acquisition of Oak Street, which has lost more than $1 billion over the last three years, could help CVS’s Medicare Advantage plans improve their quality or “star” ratings and increase payments for one of its plans.

Even small numbers of patients can translate into significant revenue. One Medical, the company Amazon owns, is best known for sleek clinics. The company scooped up a practice specializing in Medicare Advantage. Only about 5 percent of One Medical’s 836,000 members are enrolled in that federal program, but roughly half of its revenue comes from that tiny slice of patients, according to its 2022 financial statements.

Regulators are already flagging questionable methods employed by some practices. In November 2021, Oak Street disclosed that the Justice Department was investigating sales ploys like free trips to its clinics and payment of insurance agents for referrals. One doctor at a center described recruiting patients with “gift cards, swag and goody bags,” according to a shareholder lawsuit against Oak Street.

The lawsuit detailed concerns that doctors were inflating the payments from the federal government by overstating how sick their patients were.

Oak Street says it has not been accused of any wrongdoing by the Justice Department and says the lawsuit is “without merit.”

These private Medicare Advantage plans have been heavily criticized for racking up enormous profits by inflating costs and exaggerating patients’ illnesses to charge the government more than they should.

Under new rules, the Biden administration would eliminate some of the most problematic, overused diagnoses, and doctors and insurers could earn less.

But other pathways to profit also explain why corporations covet these deals. Unlike the caps on insurers’ moneymaking, where a Medicare Advantage insurer has to spend at least 85 cents of every dollar on patient care, there are no limits to how much profit these doctor practices and pharmacy chains can make.

It may be too soon to determine whether consolidated care will improve patients’ health. “So far, when you look across the industry, the record of these acquisitions has been mixed,” said Dr. Sachin H. Jain, the chief executive of SCAN Group, a nonprofit based in Long Beach, Calif., that offers Medicare Advantage plans.

And the investments may not halt the rapid disappearance of the doctor still sought by so many people for ordinary care, including a recent report showing fewer medical school graduates going into the field.

“We’re dealing with incredible levels of burnout within the profession,” said Dr. Max Cohen, who practices near Portland, Ore. Since the pandemic, his low-income patients have become much sicker, he said, with the level of illness “through the roof.”