Mark Lassise, M.D.
NPI 1023002508 · Psychiatry Physician · Mason City, IA
Enrolled with Medicare as Practitioner - Psychiatry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Lassise, M.D. is a Psychiatry Physician provider in Mason City, IA (NPI 1023002508).
Provider details
- NPI number
- 1023002508
- Entity type
- Individual
- Primary specialty
- Psychiatry PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 22919 (IA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
20 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
522 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. 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 .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 403 | $61 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 52 | $90 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 42 | $61 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 13 | $75 |
| Psychiatric Diagnostic Evaluation With Medical Services90792 | 12 | $161 |
Typical Medicare-allowed amounts for these services range $61–$161 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 19 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Buspirone Hcl | 85 | 16 |
| Quetiapine Fumarate | 66 | 15 |
| Trazodone Hcl | 58 | 16 |
| Venlafaxine Hclbrand: Venlafaxine Hcl Er | 51 | — |
| Sertraline Hcl | 51 | 15 |
| Aripiprazole | 42 | 14 |
| Olanzapine | 32 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$955 across 54 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2005-09-09
- Last updated
- 2020-07-06
- Certified
- 2020-07-06
Frequently asked questions
- What is Mark Lassise's NPI number?
- Mark Lassise's National Provider Identifier (NPI) is 1023002508, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Lassise's specialty?
- Mark Lassise is listed in the NPPES registry with a primary specialty of Psychiatry Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Lassise located?
- Mark Lassise's practice location on file with NPPES is 250 S Crescent Dr Ste 10, Mason City, IA 50401-2926.
- What is Mark Lassise's phone number?
- The practice phone number listed in the NPPES registry for Mark Lassise is (641) 494-5170.
- Does Mark Lassise accept Medicare?
- Mark Lassise is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Lassise's NPI active?
- Yes — Mark Lassise's NPI (1023002508) is active in the NPPES registry as of the last update on 2020-07-06.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.