NPI registry status
Active
2026 NPPES data Marriage & Family Therapist NPI 1508922147 PHD
Verify on CMS → Thomas Mahan, PHD
Marriage & Family Therapist in Naperville, Illinois.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 90,514 in Marriage & Family Therapist, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
What the federal data shows
Thomas Mahan, PHD is a Marriage & Family Therapist in Naperville, Illinois, listed in the federal CMS National Provider Identifier registry.
- #41
- Marriage & Family Therapist rank among Illinois specialties
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Federal trust snapshot
What official records show about Thomas Mahan, PHD
Bare NPI registry listing — limited federal enrichment beyond basic enumeration. Verify all credentials with official sources.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1508922147), first enumerated 12/28/2006.
Source: CMS NPPES
- Not in federal data
Medicare Part D participation
No 2023 Medicare Part D prescribing volume appears in the CMS public file for this NPI (may reflect specialty, new enrollment, or non-prescribing role).
Source: CMS Part D Prescriber PUF
- State context
State board disciplinary context
Illinois statewide board action statistics are published annually — these figures describe aggregate state activity, not Thomas Mahan, PHD's individual license status. Verify directly with the state medical board.
Source: IDFPR annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1508922147 · Marriage & Family Therapist
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-NONE · BOOK-LIGHT · PHOTO-ENUM
- NPI-10 1508922147
- ENUM-LEGACY 2006
- TAX-MEGA 91K Marriage &
- RX-NONE No Part D
- BOOK-LIGHT 1,228 in Illinois
- PHOTO-ENUM Susan Smith · 2006
What does the federal data show about Thomas Mahan, PHD?
Quality data not reportedPrimary specialty
Marriage & Family Therapist
Specialty distribution in Illinois
How Marriage & Family Therapist compares to other specialties among Illinois providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Marriage & Family Therapist. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Practice Address
Provider Details
| NPI | 1508922147 |
|---|---|
| Specialty | Marriage & Family Therapist |
| Credentials | PHD |
| Gender | Male |
| NPI Issued | 12/28/2006 |
License & disciplinary context - Illinois IDFPR 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~42K Illinois medical licensees in 2023 - they are NOT specific to Thomas Mahan, PHD. To verify Thomas Mahan, PHD's current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
106
Total board actions, Illinois 2023
Across 103 cases
2.52
Actions per 1,000 licensees
Illinois statewide rate
probation
Most common action type
38 cases
IDFPR publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Illinois disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Marriage & Family Therapist Overview
How Thomas Mahan, PHD fits within the Marriage & Family Therapist landscape nationally.
90,514
Marriage & Family Therapist Providers in US
55
States with Marriage & Family Therapist
246
Avg Claims per Provider
Nationwide Marriage & Family Therapist peers with similar MIPS or enrollment year
Two federal-record peer sets for Mahan, both outside Illinois so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Marriage & Family Therapist Providers in Illinois
Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as Mahan.
One of 1,228 Marriage & Family Therapist providers enrolled in Illinois, 5 are shown here.
Bithynia Abarca
MA, LMFT
Libertyville, IL
Nadine Abdelrahim
Chicago, IL
Linda Abdelsayed
Chicago, IL
Kelsey Abiera
MA, LMFT
Glen Ellyn, IL
Wendy Abraham
LMFT
Naperville, IL
Compare Marriage & Family Therapist nationally: see state-by-state distribution →
Frequently Asked Questions
What is Thomas Mahan, PHD's specialty? ▼
Thomas Mahan, PHD specializes in Marriage & Family Therapist and practices in Naperville, Illinois. Credentials: PHD.
Where is Thomas Mahan, PHD located? ▼
Thomas Mahan, PHD is located at 124 S WEBSTER ST, Naperville, IL, 60540. Phone: (630) 913-1627.
What is Thomas Mahan, PHD's NPI number? ▼
Thomas Mahan, PHD's National Provider Identifier (NPI) is 1508922147, issued on 12/28/2006.
How many Marriage & Family Therapist providers are there in the US? ▼
There are 90,514 Marriage & Family Therapist providers across 55 states in the US. The average Marriage & Family Therapist provider writes 246 Medicare Part D claims per year.
Does Thomas Mahan, PHD accept Medicare? ▼
Thomas Mahan, PHD appears in CMS Medicare data. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Thomas Mahan, PHD's credentials? ▼
Thomas Mahan, PHD's NPI is 1508922147 with credentials PHD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of August 2026 (NPPES) / 2024 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.