Mark Long, D.O.
NPI 1821475864 · Psychiatry Physician · Chillicothe, OH
Enrolled with Medicare as Order and Referring Only - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Long, D.O. is a Psychiatry Physician provider in Chillicothe, OH (NPI 1821475864).
Provider details
- NPI number
- 1821475864
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- D.O.
- Sex
- Male
- Sole proprietor
- No
- License
- 34.013837 (OH)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
11 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
1 documented practice location
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
Practice location
Mailing address
Registry dates
- Enumerated
- 2015-04-29
- Last updated
- 2023-11-17
- Certified
- 2023-11-17
Frequently asked questions
- What is Mark Long's NPI number?
- Mark Long's National Provider Identifier (NPI) is 1821475864, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Long's specialty?
- Mark Long is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Long located?
- Mark Long's practice location on file with NPPES is 17273 State Route 104, Chillicothe, OH 45601-9718.
- What is Mark Long's phone number?
- The practice phone number listed in the NPPES registry for Mark Long is (740) 773-1141.
- Does Mark Long accept Medicare?
- Mark Long is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Long's NPI active?
- Yes — Mark Long's NPI (1821475864) is active in the NPPES registry as of the last update on 2023-11-17.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.