ABC News' Paul Faris sat down with health care advocate Michelle Katz to help a family from Lake Worth, Fla., save money on its prescription medications. (Image Credit: ABC News)

ABC News' Paula Faris reports:

Of the 47.9 percent of Americans who take prescription drugs, according to the U.S. Centers for Disease Control and Prevention, most would like to save on their monthly medication bill.

Cari and Andrew of Lake Worth, Fla., who asked that their last names not be used to protect their privacy, certainly fall into that category.

Cari has Crohn's disease and requires monthly infusions. Additionally, her son Jared is on a growth hormone, and other members of the family take medicine for high cholesterol and high blood pressure. When the couple's insurance company recently pulled the plug on some of their prescription drug coverage, they were facing a $20,000 monthly bill.

To help Cari and Andrew save money on their prescriptions, ABC News brought in Michelle Katz. Katz is a health care advocate, nurse and author of "Healthcare for Less: Getting the Care You Need Without Breaking the Bank" and "Life Tips: 101 Health Insurance Tips."

Want to learn how to slash those prescription drug bills? Join Katz in a Twitter chat at 7 p.m. ET today. Check it out here: @michellekatzmsn #RealMoney or www.facebook.com/healthcareforless

1. Check your bill, like you would at a restaurant.

Believe it or not, there are codes for your drugs, and billing departments often get them wrong. In seconds, ABC News found one of those wrong codes on Cari and Andrew's bill. The couple were being charged for a higher priced drug. Fixing the code immediately saved them $1,200.

2. Arm yourself with the Low RX App.

Did you know that drug prices fluctuate like gas prices? The app tells you what the average cost is for a particular drug and its generic, and arms you with the phone numbers of every pharmacy in your area. You can call other pharmacies to comparison shop. The app also shows discounts.

"You can get up to 75 percent off in some cases," said Katz.

3. Go to big wholesalers, even if you're not a member.

The Low RX app told ABC News to go to Costco, and as it turned out, by law you could buy your prescription drugs there even if you weren't a member. ABC News found one of Cari's drugs at Costco for $100 less than elsewhere.

4. Negotiate.

If you do go to smaller mom-and-pop pharmacies, you can wheel and deal to bring the price down. Bringing cash can increase your bargaining power. Instead of paying $30 for a prescription at a local pharmacy, Cari secured the same prescription for $12 - an $18 savings.

5. You can go directly to the big drug companies.

Katz called and emailed large drug companies on behalf of Cari and Andrew. She kept at it for weeks, providing proof of the family's financial situation and even suggested that Cari might have to stop buying its particular drug altogether.

6. Visit Needymeds.com.

Needymeds is a nonprofit group that offers grants, vouchers and patient assistance through its website.

7. Use an RX Access discount card.

Together Rx Access offers savings on brand-name and generic prescription products to individuals and families without prescription drug coverage, according to its website.

With the help of Michelle Katz, Cari and Andrew lowered their monthly prescription drug bill from $20,000.19 to $1,252.28, saving them $18,747.91. And that's real money.