Mark Thielen, MFT
NPI 1851545099 · Marriage & Family Therapist · Grass Valley, CA
Mark Thielen, MFT is a Marriage & Family Therapist provider in Grass Valley, CA (NPI 1851545099).
Provider details
- NPI number
- 1851545099
- Entity type
- Individual
- Primary specialty
- Marriage & Family TherapistBehavioral Health & Social Service Providers
- Credential
- MFT
- Sex
- Male
- Sole proprietor
- Yes
- License
- 45180 (CA)
Specialties & taxonomies
Behavioral Health & Social Service Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
17 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
- 2008-11-14
- Last updated
- 2008-11-14
Frequently asked questions
- What is Mark Thielen's NPI number?
- Mark Thielen's National Provider Identifier (NPI) is 1851545099, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Thielen's specialty?
- Mark Thielen is listed in the NPPES registry with a primary specialty of Marriage & Family Therapist (Behavioral Health & Social Service Providers).
- Where is Mark Thielen located?
- Mark Thielen's practice location on file with NPPES is 698 Whiting St, Grass Valley, CA 95945-7568.
- What is Mark Thielen's phone number?
- The practice phone number listed in the NPPES registry for Mark Thielen is (530) 271-7266.
- Is Mark Thielen's NPI active?
- Yes — Mark Thielen's NPI (1851545099) is active in the NPPES registry as of the last update on 2008-11-14.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.