(CNN) Mayra Valadez still had two weeks left of her internship in the US House of Representatives when her bank balance dropped below $25.

A first-generation, low-income student from Los Angeles, Valadez had aspired to work on Capitol Hill since high school. While attending Cornell University, the only way she could afford the unpaid House internship she was offered was to use $4,000 of her scholarship money to fund the summer in Washington D.C., one of the most expensive cities in the country.

But seven weeks in, her funds ran out.

Unpaid House internships like Valadez's are common. According to a report by the nonprofit Pay Our Interns , more than 90% of House members aren't paying their interns. Broken down by party, only 8% of Republican representatives and 4% of Democrats pay their interns.

Unpaid congressional internships have been the norm since the 1990s, but that could end soon in the Senate. In June, Senators allocated $5 million to begin paying their interns. The provision is part of a broader spending bill that's currently in conference, where the House and Senate are hashing out a final version of the bill.

After this report originally published, Ohio Rep. Tim Ryan, who's the top Democrat of the House Legislative Branch Appropriations Subcommittee, secured a provision in conference committee on the larger spending bill that would provide $8.8 million for paying House interns, his office announced Wednesday. That change still needs to be voted on by the full House and Senate.

Choosing between dinner and the Metro

From taking second jobs to walking 11 miles per day to avoid Metro costs, House interns like Valadez have struggled to make ends meet for decades.

work Unpaid internships are billed by many representatives' websites as an " invaluable experience ," but an internship in Washington could cost each intern roughly $6,000, including housing, meals and transportation, according to at least one analysis of the total costs of an out-of-state internship by Time journalist Alexandra Mondalek

Faced with a financial crisis, Valadez had to say "no" to dinners with colleagues, could no longer afford healthy food and sometimes sought out events with free meals while she interned in summer 2017.

"I couldn't rely on my parents," Valadez told CNN. "They don't have the resources to help me and I knew that."

Marie Divine

Even middle-class students struggle, like 20-year-old Marie Divine from Kansas City, Kansas, who was a House intern this summer. Money is especially tight right now, Divine says, because her single mother is going into debt paying for her and her sister's educations.

While interning on the Hill, Divine worked 50 to 60 hours per week and shared one bedroom with two roommates that cost about $2,000 per month. She couldn't afford to buy food at most grocery stores and once walked 45 minutes in a downpour for a less expensive produce option. She says she often skipped lunch to save money.

"Am I going to have dinner tonight or am I going to get home on the Metro? That's really what it comes down to," Divine told CNN.

Fighting for intern pay

Members of Congress rely on interns to take constituent calls, file and answer emails and give tours to visiting constituents. Today, the decision to pay interns differs from office to office in the House.

Some members of Congress -- including Reps. Chris Stewart, Republican of Utah, Texas Democrat Joaquin Castro and North Carolina Republican Virginia Foxx -- pay their interns a stipend. Others, such as Reps. Bobby Scott, Democrat of Virginia, and Adam Smith, Democrat of Washington, pay hourly. All the offices mentioned above can pay their interns because they dip into their Members' Representational Allowance to cover intern stipends or hourly rates. Some offices offer college credit, which in effect means interns pay tuition to work there. Most representatives don't pay at all, according to Pay Our Interns.

But congressional internships weren't always unpaid. Founded in 1973, the Lyndon Baines Johnson Congressional Internship Program designated money to House offices to pay interns. However, when the program ended in 1994 , so did intern compensation in most offices.

Pay Our Interns , which prioritizes helping low-income and working-class students afford summer internships on the Hill, lobbies Democratic and Republican members of Congress to pay their interns. The organization's current mission? Pushing the House to pass legislation similar to the Senate's.

CNN reached out to dozens of congressional offices and many representatives expressed interest in paying interns, but said the situation is complicated. For example, House members are capped at hiring 18 paid staff members and four non-permanent paid staff members, and a paid intern would take up one of those slots.

California Democrat Rep. Judy Chu says that because she chairs a caucus, she frequently hits that cap.

"Many offices have difficulty finding room in their Congressionally-set budget, and pay is already too low for permanent staff," Chu said in a statement to CNN. "I support making the appropriate adjustments to change that."

A House GOP leadership aide, when asked if there were any major efforts underway by the House to allocate money for interns, noted that House offices have always been able to use their Members' Representational Allowance to pay interns. However, most choose not to.

Fierce competition for resources

Many low-income students like Valadez can only afford unpaid Hill internships because of programs that help with funding.

The daughter of Mexican immigrants, Valadez applied to the Congressional Hispanic Caucus Institute's intern program, which covers a student's travel costs, housing and Metro fees, and offers a bi-weekly stipend. But the program is extremely competitive and Valadez didn't land a spot.

Mayra Valadez

According to CHCI's Director of Leadership Programs Dennis Gonzalez, only 30 of 442 applicants for the summer 2018 program made the cut. The Congressional Black Caucus Foundation has a similar program, which, according to Vice President of Programs Anne-Marie Burton, is also highly competitive.

Outside of third-party programs like these, students have limited options.

Some, like 21-year-old Portland native Sophie Peters, a junior at Scripps College, receive grants from their schools. But even with a $4,000 grant to fund her House internship this summer, Peters says she was always searching for free meals, and sometimes took babysitting jobs in the evenings after nine-hour workdays.

A pathway to a full-time job

Students like Valadez, Divine and Peters take Hill internships because they are a proven pathway for full-time jobs as a staffer or legislative aide to House members. Valadez and Peters said that the majority of staffers in their Representatives' offices were once interns. In Divine's office, all six staffers were interns, she said.

What this means is that Hill offices are often filled with former interns who could afford to work without pay.

"Rather than the future career market being driven on talent or hard work or actual passion for the field, it seems to be divided based on who can afford to work for free when they're 20 years old," Peters said.

Pay Our Interns co-founder Carlos Vera says the cost of interning on the Hill in unpaid positions diminishes the chances for students of color and low-income students to access the intern-to-staffer pipeline. When interns are paid, the applicant pool becomes more diverse. This year, the Democratic National Committee began paying interns for the first time and the number of interns of color more than doubled from 18% to 42%

"Our goal is, how do you get the most hardworking, qualified applicants as opposed to the ones that can drop $6,000 for an internship?" Vera said.

In its second year, nonprofit College to Congress is trying to accomplish just that, according to its founder, Audrey Henson. The program fully financed congressional internships for 13 Pell Grant recipients or Pell Grant-eligible students this summer.

But Vera says that while third-party programs are valuable, they shouldn't be the only way for low-income students and people of color to afford internships on the Hill.

Working towards a solution

California Democrat Rep. Scott Peters, who does not pay his interns, confirmed he is currently working on a measure to lift the cap on paid House staff. The measure would not allocate extra money for intern pay, Peters said, but would allow existing office budgets to be redistributed to more people, including interns.

In addition to Peters' efforts, Vera says Pay Our Interns is pushing for the House to pass a line-item budget to designate money exclusively for intern pay, much like the Senate's current proposal and the former LBJ program.

Vera hopes legislation can be passed before the next fiscal year, in time to help interns next spring or summer.

Sophie Peters

Should Democrats retake the house in November, House Minority Leader Nancy Pelosi would support some type of intern reform, her spokesperson said. House Speaker Paul Ryan's office did not respond to a request for comment.

The next internship cycle begins this fall. As they look back on their summer positions, House interns like Divine say that despite the struggles, they are grateful for the opportunities. Sophie Peters, who has no relation to Rep. Peters, agreed, but made it clear that she sees room for change.

"I have a great office and I know that a lot of people do think that the interns should be paid," Sophie Peters said. "But the system as a whole is not working."

This story has been updated to include additional developments.