Doctor profile · Federal record

Dr. Aaron Lessen

Emergency Medicine Physician (CMS: Emergency Medicine) · Emergency Medicine Physician · Emergency Medicine Physician · Emergency Medicine Physician · Englewood, CO

  • NPI 1457535346
  • Accepts Medicare
  • 21 yrs in practice
  • Licensed in 3 states
  • Male
  • Group practice
  • No sanctions

Practice & contact

Operates at 2 locations .

NPPES Updated May 11, 2026
Primary practice
501 E Hampden Ave
Englewood, CO 801132702
(303) 788-6911
fax (303) 306-7753
Additional location
801 W Maple St
Farmington, NM 874015630
(505) 609-2000
Mailing address
Po Box 173862
Denver, CO 802173862

Credentials & registration

NPPES · NUCC
NPI registered
December 2007 — 19 yrs on file
Profile last updated
November 24, 2025
Year of graduation
2005 — 21 yrs since
Specialty taxonomy
207P00000X — NUCC code
State licenses (4)
Colorado #DR.0046304 · Colorado #46304 · New Mexico #MD2025-0938 · Arizona #37825
Medicaid
CO #97485870

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1457535346. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
680
Distinct HCPCS
5
Medicare allowed
$73,579
HCPCS Description Services Patients Avg allowed
99285 Emergency department visit with high level of medical decision making 277 265 $173
93010 Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only 241 218 $8
99284 Emergency department visit with moderate level of medical decision making 95 94 $119
99291 Critical care, first 30-74 minutes 55 54 $211
99283 Emergency department visit with low level of medical decision making 12 12 $71

In context: peer comparison

Among 15 peers in Englewood Emergency Medicine Physician, average services per provider: 77. This provider delivers 8.8× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$111
Transactions
1
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
Ceribell, INC. 1 $110.78

By nature of payment

Food and Beverage
$111

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
74
Patients
72
Total drug cost
$725
Drug Type Claims Patients Total cost
Ondansetron Odt (Ondansetron) Brand 28 27 $165
Cefuroxime (Cefuroxime Axetil) Brand 23 22 $398
Cephalexin Generic 12 12 $123
Prednisone Generic 11 11 $39

Frequently asked questions

Auto-generated from federal data
What is Dr. Aaron Lessen's medical specialty?
Dr. Aaron Lessen practices Emergency Medicine Physician in Englewood, CO.
Where does Dr. Aaron Lessen practice?
Dr. Aaron Lessen practices at 501 E Hampden Ave, Englewood, CO 801132702. Office phone: 3037886911.
What is Dr. Aaron Lessen's NPI?
Dr. Aaron Lessen's National Provider Identifier (NPI) is 1457535346, issued by NPPES.
Does Dr. Aaron Lessen accept Medicare assignment?
Yes. Dr. Aaron Lessen accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Aaron Lessen commonly perform?
Top Medicare-reported procedures in 2023: Emergency department visit with high level of medical decision making (HCPCS 99285); Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only (HCPCS 93010); Emergency department visit with moderate level of medical decision making (HCPCS 99284). Source: CMS Medicare Physician & Other Practitioners file.