Keith Alexander Guest, M.D.
Geriatric Medicine (Internal Medicine) Physician · Lexington, SC
Keith Alexander Guest, M.D. is a geriatric medicine (internal medicine) physician with a practice address in Lexington, South Carolina, and NPI 1285630020, issued on Jun 27, 2005. Check the license (South Carolina 20934, as entered in NPPES) on the South Carolina Board of Medical Examiners; the Medicare figures below come from public CMS files.
- Name
- Keith Alexander Guest
- Credential
- M.D.
- Primary taxonomy
- Geriatric Medicine (Internal Medicine) Physician 207RG0300X
- License number
- 20934 SC
Self-reported in NPPES; status is on the state search - Practice location
- PO Box 487, Lexington, SC 29071
- Phone
- (803) 699-9073
- Enumerated
- Jun 27, 2005
- Record last updated
- Jul 21, 2025
- Fax
- (866) 527-0937
- Medicaid ID
- GP2916 SC
- Medicare enrollment
- Enrolled (PECOS I20101019001295); accepts Medicare assignment
- Medical or professional school
- University Of South Carolina School Of Medicine, 1996
- Entity
- Type 1 · individual
8 nearest geriatric medicine (internal medicine) physician records → All 38 in South Carolina → Look up another NPI →
Also registered at PO Box 487
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Matthew Cusano, M.D.Internal Medicine Physician1740257831
- David Miller, G.N.P.Gerontology Nurse Practitioner1205832995
- Marissa MitterPhysician Assistant1124731419
Verify Keith Alexander Guest in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersSouth Carolina Board of Medical Examiners
Search for license 20934Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
82% more Medicare Part D claims than the average geriatric medicine (internal medicine) physician in 2024
7,741 Medicare Part D claims for 258 beneficiaries, against an average of 4,246 among the 3,116 providers of this specialty who prescribed in Part D. Brand-name drugs were 14% of claims. 86 claims were for opioids.
Most prescribed
- Atorvastatin Calcium513 claims
- Amlodipine Besylate422 claims
- Eliquis288 claims
- Gabapentin253 claims
- Furosemide220 claims
- Pantoprazole Sodium189 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 64.7 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Senior Health Associates, PABeaufort, SC
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Keith Alexander Guest among 38 geriatric medicine (internal medicine) physician records in South Carolina
Keith Alexander Guest, M.D. is one of 38 geriatric medicine (internal medicine) physician records with a practice address in South Carolina. 74% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 92% newer
- In a Medicare fileYes · 74% of these records are
- In the CMS Doctors and Clinicians fileYes · 58% of these records are
- Graduated1996 · median 1996 among the 22 with a school on file
- Record last updated2025 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RG0300X and a South Carolina practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Geriatric Medicine (Internal Medicine) Physician providers in South Carolina
There are 38 geriatric medicine (internal medicine) physician records in South Carolina.
All 38 in South Carolina → Every provider in Lexington → Geriatric Medicine (Internal Medicine) Physician nationwide →
The 8 geriatric medicine (internal medicine) physician records with the nearest ZIP codes
- Harry Feliciano, M.D.Elgin, SC 290451649639568
- Malissa Wilson, MDColumbia, SC 292011073529053
- John Egbert, MD PHDColumbia, SC 292031447266325
- G Eleazer, M.D.Columbia, SC 292031093782229
- Rachelle Gajadhar, M.D.Columbia, SC 292031720034879
- Victor Hirth, MDColumbia, SC 292031508835588
- Margaret Matthews, MDColumbia, SC 292031295704898
- Craig Maylath, M.D.Columbia, SC 292031326015249
Common questions
What is Keith Alexander Guest, M.D.'s NPI number?
Keith Alexander Guest, M.D.'s National Provider Identifier (NPI) is 1285630020, issued on Jun 27, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Keith Alexander Guest, M.D. located?
The NPPES record lists a practice address at PO Box 487, Lexington, SC, 29071. Phone: (803) 699-9073. Providers update this record themselves, so call before visiting.
How can I verify Keith Alexander Guest, M.D.'s license?
NPPES lists South Carolina license number 20934, as entered by the provider. Search the South Carolina Board of Medical Examiners at https://verify.llronline.com/LicLookup/Med/Med.aspx?div=22. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Keith Alexander Guest, M.D. prescribe under Medicare Part D?
In 2024, Keith Alexander Guest, M.D. had 7,741 Medicare Part D claims for 258 beneficiaries; the average among geriatric medicine (internal medicine) physician prescribers was 4,246. Part D covers Medicare prescriptions only.
What is Keith Alexander Guest, M.D.'s MIPS final score?
The 2023 MIPS final score is 64.7 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.