Michael Brian Maris, MD
Hematology/Oncology · Hematopoietic Cell Transplantation And Cellular Therapy · Medical Oncology (CMS) · Denver, CO
At a glance
1800 Williams St, Denver, CO 80218-1238
NPPES record updated Oct 1, 2013. Public records can lag behind changes at a practice.
Before you call: a quick checklist
- Are you accepting new patients?
- Do you accept my specific insurance plan?
- Do you provide the service I need at this address?
- Do I need a referral, and what is the earliest appointment?
Insurance participation and appointment availability are not established by these public records.
Medicare & insurance
Insurance participation is not established by these public records. Ask the practice and your insurer about your specific plan and this location.
How to check your coverage
Use your plan’s provider directory or the member-services number on your insurance card. Confirm the clinician, practice address, service, and whether a referral is required. A missing opt-out record does not establish Medicare acceptance.
Check the official Medicare directory ↗Practice location
1800 Williams St Ste 300Denver, CO 80218-1238
Education & affiliations
- Medical / professional school
- Perelman School Of Med At The University Of Pennsylvania
- Graduation year
- 1995
- CMS specialties
- Hematology/Oncology · Hematopoietic Cell Transplantation And Cellular Therapy · Medical Oncology
CMS reports telehealth services for this clinician. Confirm current services and availability with the practice.
Practice groups
Reported hospital affiliations
- Banner Wyoming Medical Center Casper, WY
- Hca Healthone Presbyterian St. Lukes Denver, CO
Graduation year does not establish years in practice. A reported affiliation does not establish employment, current admitting privileges, or insurance participation.
Source: CMS National Downloadable File · Published Oct 15, 2026.
Source: CMS Facility Affiliation Data · Published Oct 15, 2026.
Procedures in the public data
Reported activity can help you ask more informed questions about a practice’s services.
No displayed procedure-category record in this release. This does not mean the clinician performs no procedures.
CMS uses a one-year claims window with a reporting lag. Counts cover the Medicare activity included by CMS, not all patients. “1–10” is a published range. Volume is not a quality or outcomes score. Coverage and methodology
Source: CMS Utilization Data · Published Oct 15, 2026.
Find providers with a similar service mix
Compare 2024 published Medicare activity in the same reported specialty, here or in another city.
Industry-reported general payments
Includes reported transfers of value, such as meals, travel, or consulting. Payments do not establish improper conduct or quality of care. Research funding and ownership values are excluded from this total.
See payment purposes and reporting companies
Reported purposes
| Purpose | Amount |
|---|---|
| Food and beverage | $634.14 |
Reporting companies
| Company | Amount |
|---|---|
| ABBVIE INC. | $302.36 |
| MESOBLAST, INC. | $203.88 |
| ASTELLAS PHARMA US INC | $40.60 |
| AUTOLUS INC | $29.42 |
| CELGENE CORPORATION | $22.24 |
| DAIICHI SANKYO INC. | $18.40 |
| KITE PHARMA, INC. | $17.24 |
Source: CMS 2025 payments grouped by covered recipient and nature of payments · Published Jun 30, 2026.
Professional details: NPI, taxonomy & registry record
Registry details
- Primary taxonomy
- Hematology/Oncology · Hematopoietic Cell Transplantation And Cellular Therapy · Medical Oncology (CMS)
- Taxonomy code
- 207RH0003X
- Enumeration date
- Dec 6, 2005
- Record updated
- Oct 1, 2013
More registry details
- Provider type
- Individual · Type 1
- Reported credentials
- MD
Reported taxonomies and licenses
207RH0003X · Primary
License reported: 43475 CO
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
1800 Williams StSte 300
Denver, CO 80218-1238
- Phone
- (720) 754-4800
- Fax
- (720) 754-4801
Mailing address
4900 S MONACO ST#210
DENVER, CO 802373486
Information may be outdated or incomplete. Confirm details directly with the practice. HCPList is an independent directory and is not affiliated with CMS.
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