By Hollywood standards, the downfall had already been steep. After being implicated in the nation’s largest college admissions prosecution, Lori Loughlin resigned from her exclusive country club, downsized from her expansive Bel Air estate, and saw her acting career crater. Then, on Friday, Ms. Loughlin was sentenced to prison.

As a federal judge ordered Ms. Loughlin to serve two months behind bars for her role in the admissions scandal, he expressed astonishment that someone who had what he called “a fairy-tale life” would corrupt the college admissions system out of a desire for even more status and prestige.

Ms. Loughlin, who has acknowledged conspiring to pass her daughters off as rowers so they would be admitted to the University of Southern California, tearfully apologized. She said she had believed that she was acting out of love for her children but that she now realized she had only undermined them, as well as contributed to inequities in society.

“That realization weighs heavily on me,” Ms. Loughlin said, “and while I wish I could go back and do things differently, I can only take responsibility and move forward.”

Ms. Loughlin and her husband, the fashion designer Mossimo Giannulli, had both pleaded guilty to fraud. Prosecutors have said that they paid $500,000 as part of the scheme, although on Friday one of the couple’s lawyers suggested that the money was Mr. Giannulli’s alone. Prosecutors said Mr. Giannulli took a more active role in the fraud than Ms. Loughlin did, and the judge sentenced Mr. Giannulli on Friday to five months in prison.

Ms. Loughlin and Mr. Giannulli had fought the charges for more than a year. And at times, the focus on the boldfaced names involved in the case — which also included the actress Felicity Huffman and Douglas Hodge, the former chief executive of Pimco — eclipsed larger questions about inequities in the admissions process.

In response to the scandal, which began unfolding more than a year ago, some colleges and universities have drawn new lines between fund-raising and admissions or athletic recruitment. Others put in place safeguards to ensure that students admitted as athletes are, in fact, athletes.

The case also stirred conversations around the many advantages wealthy students enjoy in admission to selective schools, including help from high-priced tutors and coaches, opportunities to excel in sports that provide a leg up in admissions, preference given to legacy applicants, and even the option of large donations that can buy access. Lori Loughlin and Mossimo Giannulli Get Prison in College Admissions Case

For all of the changes, however, the nation’s largest college admissions prosecution, which federal law enforcement authorities called Operation Varsity Blues, did not spur as sweeping an overhaul to the admissions system at elite schools as some had expected.

“In some ways, the bad news about the Varsity Blues scandal was that it was so extreme, it enabled people to think it was ‘them’ — and not us,” said Richard Weissbourd, a senior lecturer on education at Harvard who leads a national effort to reform college admissions as part of the Making Caring Common Project. Mr. Weissbourd said he had hoped the case would prompt a deeper self-examination by schools, in which “it would all be on the table — athletes, donors, legacy, the whole thing.”

More than 50 people were charged in the case, which involved cheating on admissions tests and bribes to college coaches to falsely designate students as athletic recruits. More than 40 people have pleaded guilty or agreed to plead guilty, including William Singer, the college admissions consultant who worked with almost all of the families in the case.

No school was more deeply embroiled in the scandal than U.S.C. This week, the school acknowledged for the first time that the athletic department had passed off wealthy or connected applicants as recruits even more frequently than the college admissions case had revealed.

In a statement issued on Thursday, the university said it had discovered that, dating back to 2012, roughly a dozen students a year had been admitted as recruited athletes but ultimately did not compete. That included students who were not tied to Mr. Singer, but who were falsely presented as athletes because of “the past giving and/or potential future generosity of their families, or personal connections with employees in our athletics department,” the university said.

The university said the admissions department had been unaware of the fraud, which was perpetrated by “a small number of athletics department employees,” all of whom “have been disciplined and/or are no longer employed by the university.”

Since the case was announced in March 2019, U.S.C. has made changes to its admissions process for athletes, including requiring each head coach to certify in writing that a student is being recruited for athletic ability, and mandating that an Office of Athletic Compliance confirm that each admitted student ultimately joins a team.

Other schools, including Harvard, have put in place new, or newly official, policies around fund-raising. Harvard was not involved in the admissions case but has come under scrutiny for other issues involving donations. This year the university codified its policies on gifts; under the new rules, it will not solicit gifts from any donor known to have a family member applying for admission.

The University of Virginia now asks students being recruited for athletic teams to sign a pledge that they will actually join the team. It also prohibits its athletic department from soliciting or accepting gifts from families of students who are being recruited.

The scandal may also have contributed to growing criticism of standardized tests in college admissions. But it ultimately took a more disruptive force — the coronavirus pandemic — to cause a sea change in the use of those tests.

With many students unable to take the SAT or ACT because of the pandemic, hundreds of schools, including all of the Ivy League, have made submitting scores from such tests optional for the coming admissions cycle. The University of California, which had already been under pressure to stop requiring the tests, voted in May to phase them out permanently. While other schools have described the change as temporary, admissions officers said it was unlikely that schools would revert to their old policies, given evidence that the tests advantage wealthy students.

“There’s not very many examples of colleges and universities moving to test-optional that then move right back,” said Jonathan Burdick, the vice provost for enrollment at Cornell University, adding that he expected to see “a real reset” on the use of standardized tests.

Ms. Loughlin pleaded guilty to one count of conspiracy to commit wire and mail fraud. Mr. Giannulli pleaded guilty to one count of conspiracy to commit wire and mail fraud and honest services wire and mail fraud.

Prosecutors have said that the couple involved their daughters in the fraud. At Mr. Singer’s instruction, the couple had each daughter pose in a photograph on a rowing machine to further the ruse that she was an athlete. The daughters were also copied on emails about fake rowing profiles and registration with the National Collegiate Athletic Association, prosecutors said.

Prosecutors said the couple also advised their younger daughter, Olivia Jade Giannulli, on how to keep the scheme from her college counselor at school. When Ms. Giannulli asked her parents whether she should list U.S.C. as her top choice, Ms. Loughlin said that she should, but added, referring to the counselor, that “it might be a flag for the weasel to meddle.” Subsequently, prosecutors say, Ms. Loughlin told her daughter, “Don’t say too much to that man.”

The couple’s lawyers told the judge that being the face of the scandal had already taken a devastating toll on the family. It ended Ms. Loughlin’s acting career, they said, made it nearly impossible for her to leave her house without being trailed by paparazzi, and led to so much bullying of the couple’s daughters — on social media and in person — that the family had hired security for them.

The attorneys said Mr. Giannulli and Ms. Loughlin had not hired Mr. Singer with an intent to commit fraud. Rather, they said, Mr. Singer had been recommended as a reputable college counselor by the chairman of the board of trustees of their daughters’ school, a man named Mark Hauser.

On Friday, federal prosecutors announced that Mr. Hauser, an insurance and private equity executive, had agreed to plead guilty to a newly filed fraud charge for having conspired with Mr. Singer to cheat on the ACT for Mr. Hauser’s daughter. Mr. Hauser’s lawyer, Robert A. Fisher, declined to comment.

During the hearing, which was held over videoconference because of coronavirus concerns, Judge Nathaniel M. Gorton ordered Ms. Loughlin and Mr. Giannulli to report to prison on Nov. 19. The couple’s lawyers asked the judge to request that Ms. Loughlin be sent to a low-security prison camp in Victorville, Calif., and that Mr. Giannulli go to a similar camp in Lompoc, Calif.

This year, the camp in Lompoc had the largest outbreak of the coronavirus inside any federal prison, with more than 70 percent of inmates testing positive and two inmates dying, prison officials said. Two staff members and no inmates are known to currently have the virus, officials said. The facility in Victorville has had significantly fewer cases and no deaths.

At least two defendants in the admissions case have been released from prison early because of conditions they were being held in or because they were at risk for more severe complications from the virus.

Timothy Williams contributed reporting.