Chelsea Erin Marks, D.O.
Obstetrics & Gynecology Physician · Hanover, PA
Chelsea Erin Marks, D.O. is an obstetrics & gynecology physician with a practice address in Hanover, Pennsylvania, and NPI 1023371754, issued on Jun 18, 2012. Check the license (Pennsylvania OS018285, as entered in NPPES) on the Pennsylvania Department of State (PALS); the Medicare figures below come from public CMS files.
- Name
- Chelsea Erin Marks
- Credential
- D.O.
- Primary taxonomy
- Obstetrics & Gynecology Physician 207V00000X
- License number
- OS018285 PA
Self-reported in NPPES; status is on the state search - Practice location
- 20 North St, Hanover, PA 17331
- Phone
- (717) 637-7755
- Enumerated
- Jun 18, 2012
- Record last updated
- Dec 31, 2025
- Fax
- (717) 637-7142
- Medicare enrollment
- Enrolled (PECOS I20160928000149); accepts Medicare assignment
- Medical or professional school
- Philadelphia College Of Osteopathic Medicine, 2012
- Entity
- Type 1 · individual
8 nearest obstetrics & gynecology physician records → All 1,974 in Pennsylvania → Look up another NPI →
Also registered at 20 North St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Anita Ashton, P.A.-CPhysician Assistant1023097797
- Larissa CrownoverMidwife1427599844
- Connie Denney, P.A.-CPhysician Assistant1972582641
- Emily Grieve, CNMAdvanced Practice Midwife1629423439
- Katherine Johnson, CNMAdvanced Practice Midwife1801249743
- Jennifer Knickman, CRNPPrimary Care Nurse Practitioner1255204210
Verify Chelsea Erin Marks in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersPennsylvania Department of State (PALS)
Search for license OS018285Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
85% fewer Medicare Part D claims than the average obstetrics & gynecology physician in 2024
25 Medicare Part D claims for 13 beneficiaries, against an average of 165 among the 28,733 providers of this specialty who prescribed in Part D.
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.
Bills Medicare through 2 group practices
- Berks Community Health CenterReading, PA
- Pinnacle Health Medical ServicesHanover, PA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Chelsea Erin Marks among 1,974 obstetrics & gynecology physician records in Pennsylvania
Chelsea Erin Marks, D.O. is one of 1,974 obstetrics & gynecology physician records with a practice address in Pennsylvania. 75% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2012, is newer than 63% of them.
- NPI issued2012 · 63% of these records are older, 34% newer
- In a Medicare fileYes · 75% of these records are
- In the CMS Doctors and Clinicians fileYes · 60% of these records are
- Graduated2012 · median 2007 among the 1,176 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 207V00000X and a Pennsylvania practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Obstetrics & Gynecology Physician providers in Pennsylvania
There are 1,974 obstetrics & gynecology physician records in Pennsylvania.
All 1,974 in Pennsylvania → Every provider in Hanover → Obstetrics & Gynecology Physician nationwide →
The 8 obstetrics & gynecology physician records with the nearest ZIP codes
- Ben Montgomery, MDHanover, PA 173311255328076
- Brandi Musselman, MDHanover, PA 173311902037179
- Stephen Naymick, D.O.Hanover, PA 173311962481580
- Bezaye TeshomeHanover, PA 173311508506148
- Jessica Tocks, D.O.Hanover, PA 173311427375633
- Claudia Twum, M.D.Hanover, PA 173311346620911
- Daniel Victoria, M.D.Hanover, PA 173311134333412
- Tasneem Ahmed, MDGettysburg, PA 173251194909184
Common questions
What is Chelsea Erin Marks, D.O.'s NPI number?
Chelsea Erin Marks, D.O.'s National Provider Identifier (NPI) is 1023371754, issued on Jun 18, 2012. An NPI identifies a provider in billing; it is not a license.
Where is Chelsea Erin Marks, D.O. located?
The NPPES record lists a practice address at 20 North St, Hanover, PA, 17331. Phone: (717) 637-7755. Providers update this record themselves, so call before visiting.
How can I verify Chelsea Erin Marks, D.O.'s license?
NPPES lists Pennsylvania license number OS018285, as entered by the provider. Search the Pennsylvania Department of State (PALS) at https://www.pals.pa.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Chelsea Erin Marks, D.O. prescribe under Medicare Part D?
In 2024, Chelsea Erin Marks, D.O. had 25 Medicare Part D claims for 13 beneficiaries; the average among obstetrics & gynecology physician prescribers was 165. Part D covers Medicare prescriptions only.
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.