Simple steps for anyone who fills a prescription. Abc's paula faris helping one family to save thousands. Reporter: Cari and andrew from lake worth, florida, are living on the edge. Is this something... See More
Simple steps for anyone who fills a prescription. Abc's paula faris helping one family to save thousands. Reporter: Cari and andrew from lake worth, florida, are living on the edge. Is this something that can ruin you financially? Absolutely. We are worried about losing our home. Reporter: Like so many american family, they need and pay for several prescriptions every month, like high cholesterol and blood pressure medicine. Cari has crohn's disease and gets monthly infusions. Their son, jared, is on a growth hormone. Then, their worst nightmare. Suddenly, their insurance company told them they won't cover all of it. They are now facing a $20,000 bill every month. Are you guys afraid right now? Yes. Yeah. Reporter: So, we brought in michelle katz, a health care advocate. Tip number one, check your bill, like you do at a restaurant. Believe it or not, there are codes for your drugs and often they get them wrong. We found one of those wrong colds, fixed it and immediately saved them $1,200. Tip two, arm yourself with this app, called low rx, and here's why. Did you know drug prices fluctuate like gas prices? Different pharmacies can charge different prices for the same drug? Right. Reporter: The app tells you the average price of the drug, including generics, and arms you with of every pharmacy in the area. We found one of cari's drug 100 does cheaper at costco. And you can still fill prescriptions at those big wholesalers. I can still get it filled here, no questions asked? That's correct. Reporter: And that's by law? Correct. Reporter: If you go to the small mom and pop pharmacies, you can wheel and deal to bring the price down. You ready to negotiate? Absolutely. That's $30. Reporter: If I bring in cash, is there more bargaining power? He goes back to check, and when he returns, a deal. Reporter: Because she paid cash, it went from $30 to $12. That's correct. Reporter: And you can go directly to the big drug companies. Michelle kept at it for weeks, gave them proof of the family's finances, telling them cari might have to stop buying the drug altogether. They were there when they learned what was going to cost them over 17 grand a month will call them $411. Are you okay? I see a tear. It's a big burden. Yeah. Now I'm starting to cry. Reporter: It's okay. Did you think that this would be possible? No. Great news for them. You're with us now, paula, holding a twitter chat tonight using #realmoney. Costco, who knew? Reporter: You don't have to president a member. Head straight to the pharmacy. It's the law. Paula faris, thank you.
This transcript has been automatically generated and may not be 100% accurate.