IndividualActive
Mary Johnston, RN
NPI 1659595494 · Registered Nurse First Assistant · Naperville, IL
Mary Johnston, RN is a Registered Nurse First Assistant provider in Naperville, IL (NPI 1659595494).
Provider details
- NPI number
- 1659595494
- Entity type
- Individual
- Primary specialty
- Registered Nurse First AssistantNursing Service Providers
- Credential
- RN
- Sex
- Female
- Sole proprietor
- No
- License
- 41199041 (IL)
Specialties & taxonomies
Nursing Service Providers
Profile Score
Detailed profile(89/100 index)
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
19 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
120 Osler Drive
Naperville, IL 60540
Phone: (630) 428-2229
Street-level locationGet directions
Mailing address
27555 Diehl Rd.
Warrenville, IL 60555
Registry dates
- Enumerated
- 2007-04-12
- Last updated
- 2007-07-08
Frequently asked questions
- What is Mary Johnston's NPI number?
- Mary Johnston's National Provider Identifier (NPI) is 1659595494, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mary Johnston's specialty?
- Mary Johnston is listed in the NPPES registry with a primary specialty of Registered Nurse First Assistant (Nursing Service Providers).
- Where is Mary Johnston located?
- Mary Johnston's practice location on file with NPPES is 120 Osler Drive, Naperville, IL 60540.
- What is Mary Johnston's phone number?
- The practice phone number listed in the NPPES registry for Mary Johnston is (630) 428-2229.
- Is Mary Johnston's NPI active?
- Yes — Mary Johnston's NPI (1659595494) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.