There are nearly 2,100 South Florida businesses licensed by Medicare to sell medical supplies such as wheelchairs, artificial limbs and home oxygen equipment. Miami-Dade County has the most, with 931 active providers, followed by Broward County, 782, and Palm Beach County, 385.

Last year, a critical federal government report found that almost half of Miami-Dade's medical equipment companies didn't have a place of business, weren't open to the public or didn't meet minimal operational standards.

To obtain a Medicare license and remain in business, a durable medical equipment provider must meet 21 federal standards. Among them, a supplier must:

• Maintain a facility and regular business hours.

• Post a visible sign, hours of operation and telephone number.

• Fill patient orders from its own inventory or another approved contractor.

• Have at least $300,000 in liability insurance for the business and customers.

• Notify Medicare of ownership or other changes in the business license.

• Permit Medicare authorities to conduct inspections.

Source: U.S. Department of Health and Human Services, Office of Inspector General; Centers for Medicare and Medicaid Services.