Most part-time university professors are paid quite modestly, but that rule does not appear to apply to some Members of Congress who dabble in academia.

The average adjunct faculty member earns anywhere from $3,000 to $6,000 per course, and possibly as much as $10,000 at the graduate level, according to experts in the field, though universities have wide latitude to set salaries for part-timers.

But last year, Reps. Barbara Lee (D-Calif.), Richard Neal (D-Mass.) and Jim Cooper (D-Tenn.) all made $20,000 or more as adjunct faculty at universities in their home states, with a lighter course load than an ordinary adjunct would have to teach to earn that much.

All of the Members say that their teaching deals were approved by the House ethics committee, which requires a certification from the university that “the compensation does not exceed that normally received by others at the institution for a comparable level of instruction and amount of work.” Members are allowed to earn up to $25,830 in outside income.

But John Curtis, director of research and public policy at the American Association of University Professors, said of the Members’ teaching fees, “That’s a special deal. … That’s not what regular part-time faculty are getting.”

Bill Allison, senior fellow at the Sunlight Foundation, said that given the dependence of universities on government funding, anytime a Member of Congress is on an academic payroll, it raises questions about a potential conflict of interest.

For example, three years ago, Lee secured $320,000 in federal funding for her alma mater — Mills College, in Oakland, Calif. — to establish an institute for civic leadership. Two years ago, the college received a private donation to establish the “Barbara Lee Distinguished Chair in Women’s Leadership.” And last year, Mills College paid her $20,000 as an adjunct faculty member to team-teach one course, according to Lee’s 2007 personal financial disclosure form.

The class Lee taught in the spring of 2007 and again in the spring of 2008 was a truncated half-credit class, meeting on Saturdays for seven weeks, instead of the normal 13 or 14 weeks in a semester, according to Andrew Workman, vice provost at Mills College. This year, Lee team-taught the course — called “Real Policy, Real Politics” — with the faculty member who occupies the Barbara Lee Distinguished Chair.

The Committee on Standards of Official Conduct sent Lee an approval letter in January 2007, saying that Lee had indicated that she “would receive $6,000 for teaching the course, which [the college president] indicates is the standard compensation paid to adjunct faculty at Mills.” Lee’s office could not explain why her compensation from the course had grown to $20,000, and Lee was traveling and unavailable to comment Tuesday.

Workman said the average adjunct at Mills earns closer to $7,500, so Lee’s compensation “is not completely out there. … It’s on par with someone of her qualifications.” Workman pointed out that “we from time to time get distinguished writers” who are paid an adjunct salary comparable to Lee’s.

Workman also said that Lee “has a tremendous attachment to the college,” and frequently cites her student days there as a turning point in her life.

Cooper’s deal at Vanderbilt — $22,500 for teaching “Healthcare Law and Regulation” in the semester — also appears to be generous, but it is harder to evaluate an average salary because he is paid by the Owen School of Management.

Business schools tend to pay more than other academic institutions, and Cooper taught there in the late 1990s between his stints in Congress. Cooper left Congress in 1994 to run for the U.S. Senate; he lost, but was re-elected to the House in 2002. His 2003 financial disclosure report indicated that his salary at Vanderbilt was $20,000, though it is not clear if he taught in both semesters.

A letter from the dean of the Owen School that Cooper submitted to the ethics committee last year indicated that Cooper also received “a $2,500 course preparation stipend,” meaning that his base pay hasn’t changed since before he returned to Congress. That same letter states that Cooper’s compensation “is in a range comparable to the compensation paid to others in similar situations at the University.”

Cooper has provided millions of dollars worth of earmarks for Vanderbilt over the years, and in 2006 he requested more than $40 million for the university’s research programs, according to local news reports. But there is no indication that any of those earmarks went to the Owen School, and Cooper has said that he will not seek earmarks this year.

Neal’s deal with the University of Massachusetts-Amherst paid him $21,000 last year for a single course taught in the spring and fall semesters called “The Politician and the Journalist.” Neal has been teaching the course for about a decade, and the handful of student reviews on the Web site Ratemyprofessors.com suggest that students enjoy the class and consider Neal an easy grader.

Amherst is just outside Neal’s Congressional district, and “he has not sought or secured any earmarks for the university,” said spokesman William Tranghese. “His participation in this program has been approved each year by the Committee on Standards of Official Conduct. His salary is determined exclusively by the University of Massachusetts,” Tranghese said.

Three other House members reported on their 2007 financial disclosures that they were adjunct faculty, though for much lower pay.

Del. Eleanor Holmes Norton (D-D.C.) was a faculty member at Georgetown University Law Center prior to running for office, and she has continued to teach there during her tenure in Congress. Her yearlong seminar is called “Lawmaking and Statutory Interpretation,” and last year she was paid $10,200 to teach.

Rep. Robert Brady (D-Pa.) team-teaches a course at the University of Pennsylvania on organizational dynamics, and essentially takes no salary. Brady’s financial disclosure form lists his income from Penn as $3; his spokeswoman said she thought it was $1 and Brady never cashes the checks anyway. The salary is simply a way to keep him on the university’s books, she said.

Rep. Tim Murphy (R-Pa.) reports being an unpaid adjunct faculty member at the University of Pittsburgh, but his office says he has not taught a full course since he was elected to Congress in 2002.

Torey Van Oot contributed to this report.