Shirley Pak So, M.D.
Geriatric Medicine (Internal Medicine) Physician · Worcester, MA
Shirley Pak So, M.D. is a geriatric medicine (internal medicine) physician with a practice address in Worcester, Massachusetts, and NPI 1639466592, issued on Jun 29, 2011. Check the license (Massachusetts 249041, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Shirley Pak So
- Credential
- M.D.
- Primary taxonomy
- Geriatric Medicine (Internal Medicine) Physician 207RG0300X
- License number
- 249041 MA
Self-reported in NPPES; status is on the state search - Practice location
- 291 Lincoln St, Worcester, MA 01605
- Phone
- (508) 334-6251
- Enumerated
- Jun 29, 2011
- Record last updated
- May 1, 2022
- Fax
- (508) 334-6906
- Medicare enrollment
- Enrolled (PECOS I20110922000164); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest geriatric medicine (internal medicine) physician records → All 225 in Massachusetts → Look up another NPI →
Also registered at 291 Lincoln St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Hawa Abu, MDGeriatric Medicine (Internal Medicine) Physician1104441229
- Linsey BarkerGeriatric Medicine (Internal Medicine) Physician1356847974
- Jessica Boatman Dray, M.D.Geriatric Medicine (Family Medicine) Physician1528487857
- Alexis Brenya, MDPediatrics Physician1548962400
- Tracy Cormier, NPNurse Practitioner1083829014
- Ronald Cruz, MDInternal Medicine Physician1710962154
Verify Shirley Pak So in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 249041Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
84% more Medicare Part D claims than the average geriatric medicine (internal medicine) physician in 2024
7,822 Medicare Part D claims for 172 beneficiaries, against an average of 4,246 among the 3,116 providers of this specialty who prescribed in Part D. Brand-name drugs were 16% of claims. 32 claims were for opioids.
Most prescribed
- Eliquis484 claims
- Furosemide461 claims
- Levothyroxine Sodium455 claims
- Mirtazapine439 claims
- Atorvastatin Calcium290 claims
- Trazodone Hcl288 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 MIPS final score for 2023 (Medicare payment program): 97 of 100
The Merit-based Incentive Payment System score is reported for this clinician. 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; category weights for 2023 (qpp.cms.gov).
Bills Medicare through one group practice
- Umass Memorial Medical Group IncWorcester, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Shirley Pak So among 225 geriatric medicine (internal medicine) physician records in Massachusetts
Shirley Pak So, M.D. is one of 225 geriatric medicine (internal medicine) physician records with a practice address in Massachusetts. 71% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2011, is newer than 76% of them.
- NPI issued2011 · 76% of these records are older, 22% newer
- In a Medicare fileYes · 71% of these records are
- In the CMS Doctors and Clinicians fileYes · 53% of these records are
- Graduated2004 · median 2000 among the 119 with a school on file
- Record last updated2022 · 63% 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 Massachusetts 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 Massachusetts
There are 225 geriatric medicine (internal medicine) physician records in Massachusetts.
All 225 in Massachusetts → Every provider in Worcester → Geriatric Medicine (Internal Medicine) Physician nationwide →
The 8 geriatric medicine (internal medicine) physician records with the nearest ZIP codes
- Hawa Abu, MDWorcester, MA 016051104441229
- Linsey BarkerWorcester, MA 016051356847974
- Jeffrey Burl, MDWorcester, MA 016051699749309
- David Dosa, MDWorcester, MA 016051417901687
- Kouta Ito, M.D., M.S.Worcester, MA 016051295905115
- Suhasini Iyer, M.D.Worcester, MA 016051063495943
- Vijay Kajla, MDWorcester, MA 016051285616888
- Zahra Sheikh, MDWorcester, MA 016051851389522
Common questions
What is Shirley Pak So, M.D.'s NPI number?
Shirley Pak So, M.D.'s National Provider Identifier (NPI) is 1639466592, issued on Jun 29, 2011. An NPI identifies a provider in billing; it is not a license.
Where is Shirley Pak So, M.D. located?
The NPPES record lists a practice address at 291 Lincoln St, Worcester, MA, 01605. Phone: (508) 334-6251. Providers update this record themselves, so call before visiting.
How can I verify Shirley Pak So, M.D.'s license?
NPPES lists Massachusetts license number 249041, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Shirley Pak So, M.D. prescribe under Medicare Part D?
In 2024, Shirley Pak So, M.D. had 7,822 Medicare Part D claims for 172 beneficiaries; the average among geriatric medicine (internal medicine) physician prescribers was 4,246. Part D covers Medicare prescriptions only.
What is Shirley Pak So, M.D.'s MIPS final score?
The 2023 MIPS final score is 97 of 100. 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.