Grad work is completely separate from undergrad and doesn't touch undergrad GPAs.
so an SMP is just undergrad classes and no work towards a degree or certification?
Doesn't sound like you've been in the postbac forum. I've literally written 2000+ excruciatingly detailed posts about the what and why of SMPs in the postbac forum. Nor do you seem to be familiar with any SMPs. So I'll assume you're asking rhetorically.
Med school is
technically undergrad. Residency is GME, graduate medical education.
The
S in SMP means special, which preferably means you're sitting in med school classes next to med students taking the same exams. There is no purpose in doing an SMP other than auditioning for med school, in a way that med schools can understand fairly easily.
But the
M in SMP usually means
masters. Usually you get a Masters in Biomedical Sciences, or an MA, after successful completion of an SMP, for the coursework you take with med students, which is technically undergrad for the med students. Usually this works out in terms of grad degree accreditation because there's also a library thesis and/or seminar coursework etc for the SMP students (who can't take the clinical coursework with the med students, which is maybe 10% of the 1st year curriculum).
Note: there are programs with STELLAR records of getting low-ish GPA premeds into US MD schools, which are not SMPs by my snotty definition. Loyola MAMS is a grad program that doesn't include med school classes with med students. Great program. VCU has a postbac certificate program that sometimes includes med school classes, and it's undergrad. Great program. US MD adcoms are not even slightly confused about these programs and their reputations. It's a complete waste of time to argue about whether to call them SMPs or not.
So how does an SMP that grants a masters factor into med school admissions? The SMP GPA goes in grad, which doesn't help with autoscreens at all. A sub-3.0 uGPA is still going to get autoscreened out at a lot of schools despite a 4.0 in an SMP.
If and when a reviewer looks past a low-ish uGPA, and sees a recovery story that includes a strong SMP performance, then that app might effectively land on the same playing field as the rest of the premeds. A low-ish GPA med school app has to make it in front of eyeballs to get consideration for an SMP performance. Generally the best odds of a US MD acceptance are at a premed's home state public schools.
There are boatloads of SMP students at programs like Gtown that got interviews and maybe even waitlists prior to starting the SMP. These students use the SMP to show commitment, to defer student loans, and to maybe slightly nudge their reapp with their
enrollment in an SMP. Being enrolled in an SMP is otherwise no asset in a low-ish GPA med school app. Gotta get some grades & letters. IMHO a same-year-as-SMP US MD app is a terrible idea unless you got interviewed & preferably waitlisted before. (Unless you're at Temple or Tulane ACP, which have 95%+ results of host school acceptance same-year-as-SMP. These programs are obviously very selective.)
There are boatloads of terminal one-year masters, not hosted at med schools, that absolutely LOVE IT when they get called SMPs. Any degree-granting college in the US can offer a one year masters in bioscience, describe it as an "academic enhancement" program, and face exactly no consequences if grads don't get into med school afterwards.
So in general if you have a premed with say a 3.2-3.4 and say a 515, completely ready for the rigors of med school, with compelling app assets, that's a pretty good candidate for an SMP. An SMP does absolutely nothing for a low MCAT. An SMP is a mistake for a student who has an unproven undergrad record such as a cuGPA of <3.0 that
lacks a very strong, multiple-year, mostly-science full time undergrad performance such as a 2nd bachelors.
DO "SMPs" typically don't have "S" in terms of sitting with med school students in med school classes, but they're a great option for getting ready for med school and getting into a DO school.
For further discussion I suggest visiting the postbac forum.
Best of luck to you.