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Internal Medicine

Merrill M. Ahrens, MD

Works at hospitals in Portland, OR · Oregon

Summary

Dr. Merrill M. Ahrens, MD is an internal medicine doctor at 1130 NW 22nd Ave, Suite 220, Portland, OR 97210. Phone: (503) 413-8988. Accepts Medicare assignment. In 2024, Merrill M. Ahrens had 215 Original Medicare patients and 541 services. NPI 1194839225. Source: CMS National Downloadable File, updated October 2, 2026; CMS Facility Affiliation Data, updated October 2, 2026; CMS Medicare Physician & Other Practitioners, data year 2024.

From official Medicare data

This page shows what Medicare's official clinician data says about Merrill M. Ahrens, joined by NPI number (data updated October 2, 2026). It is not a recommendation or a rating. Call the office or hospital to confirm before you go.

In a medical emergency, call 911.

Quick answers

Does Merrill M. Ahrens accept Medicare assignment?
Yes. Medicare's clinician data says Merrill M. Ahrens accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of October 2, 2026. Ask the office to confirm before your visit.
How many Medicare patients does Merrill M. Ahrens see?
In 2024, CMS data shows 215 Original Medicare patients and 541 services for Merrill M. Ahrens. This counts Original Medicare only and measures volume, not quality.
What is Merrill M. Ahrens's NPI number?
1194839225. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.

Medicare activity in 2024

Official CMS public-use data for Merrill M. Ahrens, data year 2024 (released May 21, 2026). It covers Original Medicare (fee-for-service) patients only, not Medicare Advantage or other insurance. It shows volume, not quality or outcomes. CMS hides any count of 10 or fewer patients.

Original Medicare patients215
Services billed to Medicare541
Different services or procedures34
Participating Medicare providerYes
Average age of these patients71

Most frequent services

  1. Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's (G2211)209 services
  2. Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more (99213)171 services
  3. Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more (99214)29 services
  4. Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more (99215)18 services

Chronic conditions among these patients

Share of this clinician’s Original Medicare patients with each condition, as published by CMS (it describes the patients, not the care given).

  • High blood pressure65%
  • High cholesterol59%
  • Arthritis40%
  • Depression28%
  • Anxiety28%
  • Ischemic heart disease24%

Hospitals where Merrill M. Ahrens works

Medicare's Facility Affiliation Data lists Merrill M. Ahrens at these hospitals (updated October 2, 2026). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians. Star rating and emergency services: Hospital General Information (CMS), data updated October 26, 2026.

Practice locations

Addresses where Merrill M. Ahrens is enrolled with Medicare (CMS data updated October 2, 2026).

Group practices

Medicare enrollment lists Merrill M. Ahrens as a member of these groups (CMS data updated October 2, 2026).

  • Legacy Clinics LLC713 clinicians in the group
  • Legacy Emanuel Hospital and Health Center238 clinicians in the group
  • Legacy Good Samaritan Hospital and Medical Center191 clinicians in the group

Specialties

Find other Internal Medicine doctors in Oregon →

Other internal medicine doctors in Portland

Clinicians with the same Medicare primary specialty in Portland, OR — not a recommendation.

All internal medicine doctors in Portland →

Other clinicians in Legacy Clinics LLC

Medicare enrollment lists these clinicians in the same group practice — not a recommendation.

Clinician information

CredentialMD
Medical schoolNorthwestern University Feinberg Medical School
Graduation year1989 (37 years since medical school)
Gender (as listed)Male
Medicare assignmentAccepts (Medicare-approved amount as full payment)
TelehealthOffers telehealth services
NPI (National Provider Identifier)1194839225
CorrectionsReport an error or suggest an update →

Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.

Sources

  1. Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated October 2, 2026, retrieved October 29, 2026
  2. Hospital General Information — CMS, data updated October 26, 2026, retrieved November 13, 2026
  3. National Downloadable File (Doctors and Clinicians) — CMS, data updated October 2, 2026, retrieved October 29, 2026
  4. Medicare Physician & Other Practitioners - by Provider — CMS, data year 2024, released May 21, 2026; Medicare Physician & Other Practitioners - by Provider and Service
  5. NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
  6. Medicare Care Compare — official Medicare tool to look up clinicians