The costs of medical attention can be exorbitant for a low-income family or an unemployed person -- even if the needs are the same.
"We don't ask you whether you have insurance, or whether you have a job, or are you a citizen of the United States," Brock told CNN.
RAM started as an airborne overseas operation where medical attention was provided to the most remote of areas. Now, about 60 percent of the work RAM does is in the U.S., with around 85 percent of the patients seeking dental and vision work, the news outlet reports.
"I understand what it's like to be penniless, homeless and uninsured," said Brock, who moved from England to what was then British Guiana, working as a cattle herder after dropping out of school at 16. The former cowboy sometimes went days without food and water, according to CNN.
All the medical professionals are volunteers -- paid, according to Brock -- in gratitude.
"The patients are marvelous, so grateful for what we were able to do for them," Brock said. "There's just no feeling like that -- knowing that you've helped someone. It's just great."