The point
LizzyM is making (much better than me) is that the socioeconomic demographics of an area or population are irrelevant to the definition of "underserved." You can have a poor neighborhood that is not underserved. You can have a rich neighborhood that is underserved. The definition considers only available supply of medical providers, not patient characteristics.
Sorry, but I'm actually going to have to disagree here, and with
@LizzyM, as rare as that is.
There's a reason the feds use infant mortality and poverty as a metric in their definition. What makes a population underserved is way way more complicated than just a ratio of doctors to population. Furthermore, it's not really "areas" that are important in talking about the underserved. It's populations that matter. Those can vary block by block or even house by house.
As a real life example, I have two patients in my clinic that I see regularly, both about the same age with similar issues. One lives 3 blocks east of my hospital, and one block north. The other lives 3 blocks east, and one block south. They both share the same bus stop, but the differences in their ability to access care couldn't be more stark. One works an administrative job at my institution, the other lives in a public housing project and worked minimum wage jobs until an accident put her on SSI. The latter has mobility issues and requires use of our city's awful paratransit system to get to appointment, which drops her off 3 hours before her appointment and picks her up an hour after it ends. She's also had issues getting her medications at our pharmacy 2/2 a very specific issue with our state's medicaid that was only corrected last year (which usually required me to deal with hour-long hold times on the phone...otherwise no meds). To make matters even more fun, her young adult son had a psychotic break 3 years ago and now gets taken advantage of by local street gangs which has put her own personal safety at risk, so she's not leaving the home much anymore except for her appointments... which as I said requires our sh-t paratransit system. The former can call a cab.
I'm available and could realistically schedule an appointment with either of them whenever they needed an appointment. It's not just an issue of access to me or any of the other MDs out there. The latter patient requires a much greater burden of resources (social work assistance, public services, etc) for the upkeep of very similar medical problems with very similar treatments. Delivery of medical care requires more than just doctors and nurses. It requires a functioning social structure, and in this day and age, there aren't many municipal and state governments capable of meeting the needs of these patients sufficiently*. I have countless other patients in similar or worse situations that I've had to close out this week now that I'm leaving my institution.
I'll go further to address the OP's original predicament.
The reason schools would like to see a commitment to and experience with the underserved isn't just because they want someone to open a clinic in a well-to do area that could use a new family doc to decrease an area's wait time for an initial appointment. If that was the case, why would schools care? Anyone could do that. It's because to put it bluntly and painfully, the truly underserved are underserved for a reason. Working with these communities that lack the resources to sustain the social needs of their inhabitants* requires far more personal effort and patience than with the patients who are similar to the people that assumedly you or I had as neighbors growing up. Quite simply, even though I enjoy the patients I work with and I think my residency did a great job putting me in this challenging environment to make me a better physician, sometimes working with them is just ....really...f-cking...draining. It's required a massive development of my own skills to get patients who've grown up sexually abused from the time they were 4, to later being homeless living as a prostitute as a teenager just to survive to trust my medical advice, and I think I've become quite good at it, but sometimes after hearing some of the things I hear even during a 20 minute appointment, I just want to come home, sit, drink a beer, and not think about anything at all. If you're the type of person who
truly wants to dive into that, then that's worth more than a couple MCAT points to me.
*obviously I'm doing the urban thing, but from talking to people at the other ends of the spectrum, the challenges for rural populations aren't dissimilar.