Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Ann M. Mass, MD, PC

Organization Internal Medicine Physician · NPI 1831388008

Ann M. Mass, MD, PC is an Internal Medicine Physician in Aspen, Colorado. Licensed in Colorado. Registered with an NPI since 2007.

Licensed in
CO
In the registry since
2007
What do these letters mean?
PC — Professional corporation
A form of business registration, not a clinical qualification.

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Practice location Address checks out

225 N Mill St Ste 116
Aspen, CO 81611-1559
Phone: (970) 544-1234
Fax: (970) 544-1310
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 21624 (CO)

Record details

NPI number1831388008
Entity typeOrganization (Type 2)
Organization subpartNo
Authorized official Ann Mass — Physician · (970) 544-1234
NPI enumeratedOctober 23, 2007
Last updated in NPPESJuly 28, 2008
Mailing address225 N Mill St, Suite 116, Aspen, CO 81611-1559

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