Donald Markham
NPI 1659815561 · Addiction (Substance Use Disorder) Registered Nurse · Oshkosh, WI
Donald Markham is a Addiction (Substance Use Disorder) Registered Nurse provider in Oshkosh, WI (NPI 1659815561).
Provider details
- NPI number
- 1659815561
- Entity type
- Individual
- Primary specialty
- Addiction (Substance Use Disorder) Registered NurseNursing Service Providers
- Sex
- Male
- Sole proprietor
- No
- License
- 226325-30 (WI)
Specialties & taxonomies
Nursing Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
9 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
- 2016-12-12
- Last updated
- 2016-12-12
Frequently asked questions
- What is Donald Markham's NPI number?
- Donald Markham's National Provider Identifier (NPI) is 1659815561, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Donald Markham's specialty?
- Donald Markham is listed in the NPPES registry with a primary specialty of Addiction (Substance Use Disorder) Registered Nurse (Nursing Service Providers).
- Where is Donald Markham located?
- Donald Markham's practice location on file with NPPES is 505 S Washburn St, Oshkosh, WI 54904-7949.
- What is Donald Markham's phone number?
- The practice phone number listed in the NPPES registry for Donald Markham is (920) 232-2332.
- Is Donald Markham's NPI active?
- Yes — Donald Markham's NPI (1659815561) is active in the NPPES registry as of the last update on 2016-12-12.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.