OrganizationActive
John Gregory Duffy MD, Apc
NPI 1093985137 · Psychiatry Physician · Tustin, CA
John Gregory Duffy MD, Apc is a Psychiatry Physician organization in Tustin, CA (NPI 1093985137).
Provider details
- NPI number
- 1093985137
- Entity type
- Organization
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Organization subpart
- No
- Authorized official
- John Duffy, President(714) 669-3198
- License
- A054948 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
Detailed profile(87/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
18 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
17821 E 17st
Suite 165
Tustin, CA 92780-2136
Phone: (714) 669-3158
Fax: (714) 669-3198
Street-level locationGet directions
Mailing address
17821 E 17st
Tustin, CA 92780-2136
Registry dates
- Enumerated
- 2008-03-05
- Last updated
- 2008-03-11
Frequently asked questions
- What is John Gregory Duffy MD, Apc's NPI number?
- John Gregory Duffy MD, Apc's National Provider Identifier (NPI) is 1093985137, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What type of organization is John Gregory Duffy MD, Apc?
- John Gregory Duffy MD, Apc is classified in the NPPES registry as Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is John Gregory Duffy MD, Apc located?
- John Gregory Duffy MD, Apc's practice location on file with NPPES is 17821 E 17st, Tustin, CA 92780-2136.
- What is John Gregory Duffy MD, Apc's phone number?
- The practice phone number listed in the NPPES registry for John Gregory Duffy MD, Apc is (714) 669-3158.
- Who is the authorized official for John Gregory Duffy MD, Apc?
- The authorized official listed on John Gregory Duffy MD, Apc's NPPES record is John Duffy, President. The authorized official registers and maintains the organization's NPI and is not necessarily its owner.
- Is John Gregory Duffy MD, Apc's NPI active?
- Yes — John Gregory Duffy MD, Apc's NPI (1093985137) is active in the NPPES registry as of the last update on 2008-03-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.