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Edit this profileAt a glance
- 24221 Calle de la Louisa, Suite 200, Laguna Hills, CA 92653
About Dr. Shields
Mark D. Shields, MD practices internal medicine in Laguna Hills, CA. Mark is a 1992 graduate of University of California, Geffen School of Medicine. Medicare claims data shows Mark provided 1,055 services to 816 patients. The services billed most often include established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more, established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more, and annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit. The provider's National Provider Identifier (NPI) is 1366411555.
Factual summary compiled by Guide.md from public records; not written by this provider.
Education & Training
Specialty
Credentials & Licensing
Medicare information
Exactly as CMS reports it (National Downloadable File, Opt-Out Affidavits, Order & Referring). Not an insurance directory; confirm coverage with the office.
Contact Information
- (949) 588-8700
- Email not available
Practice Locations
24221 CALLE DE LA LOUISA SUITE 200
Laguna Hills, CA 92653
Conditions Commonly Evaluated or Treated
Within Internal Medicine generally. Availability varies by clinician, training and location — this profile has not been claimed, so nothing here is a personal claim by the provider.
Conditions
Most searched conditions
- Allergies
- Diabetes
- Flu
- Hypothyroidism
- Strep throat
- UTI
Cardiometabolic
Digestive and liver
Endocrine, blood, and bone
Infectious disease
Kidney and urinary
Respiratory
Blood & Circulation
Blood disorders
Brain & Nerves
Brain and nerves
- Vertigo
Cardiac and vascular
Digestive
Heart & Circulation
Infections
Kidney & Bladder
Lungs & Breathing
Mental Health
Neurologic and behavioral
Pain
Rheumatologic and pain
Procedures & services
Most searched procedures
- Annual physical
- Blood test
- Flu shot
- Medicare wellness visit
- Sick visit
- TB test
- Well-woman exam
Preventive and evaluation
- Medication management
- Post-hospital transitional care
Screening and diagnostic testing
Bones & Joints
Brain and nerves
Cancer screening
- Colon Cancer Screening Referral
- Mammogram Referral
Digestive
Exams & Consultations
- Pre-Op Clearance Exam
Heart & Circulation
Heart health
- Cardiac Stress Test Referral
Imaging referral
- Abdominal Ultrasound Referral
Immunizations
Lab tests
- Urinalysis
Lungs & Breathing
- At-Home Sleep Study Order
Metabolic & Weight
- Weight Loss Injections and Medication
Minor procedures
- Ingrown toenail removal
- Suture removal
Office procedures
Office Procedures
- Skin Tag and Mole Removal
- Vitamin B12 Injections
- Wart Removal
Pain management
Preventive & Routine Care
Screenings & Diagnostics
- Bone Density Scan Referral
- Diabetes Screening and A1C Test
Sexual health
- STI Testing
Procedures Most Often Billed to Medicare
1,055 services · 816 patients · 18 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Insertion of needle into vein for collection of blood sample | Procedure | 36415 |
43 | Less often than most peers in Internal Medicine |
| Influenza vaccine, inactivated | Treatment | 90653 |
34 | As often as other peers in Internal Medicine |
| Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report | Treatment | 93000 |
17 | Less often than most peers in Internal Medicine |
| Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more | Office visit | 99214 |
354 | More often than most peers in Internal Medicine |
| Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more | Office visit | 99213 |
203 | More often than most peers in Internal Medicine |
| Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit | Billing code | G0439 |
92 | As often as other peers in Internal Medicine |
| Blood test, comprehensive group of blood chemicals | Lab test | 80053 |
40 | Less often than most peers in Internal Medicine |
| Administration of influenza virus vaccine | Billing code | G0008 |
36 | As often as other peers in Internal Medicine |
| Office or other outpatient visit for the evaluation and management of established patient that may not require presence of healthcare professional | Office visit | 99211 |
33 | As often as other peers in Internal Medicine |
| Blood test, lipids (cholesterol and triglycerides) | Lab test | 80061 |
31 | Less often than most peers in Internal Medicine |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Other internists at this location 8
Same specialty, same street address — most likely the same department or group.
Related specialists at this location 8
Clinically related specialties at the same address — the people this provider most likely works alongside.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
More connections — 30 related providers in 4 groups
Other internists in Laguna Hills 7
Same specialty, same city.
Trained at University of California, Geffen School of Medicine 8
Other providers in the same specialty who trained at the same institution.
Class of 1992 at University of California, Geffen School of Medicine 7
Providers who graduated from the same medical school in the same year.
Also performs Insertion of needle into vein for collection of blood sample 8
Providers in CA who bill this service to Medicare most often.
Common questions
What does Dr. Shields specialize in?
Dr. Shields is an internist in Laguna Hills, CA. That is the designation recorded for this NPI in the federal registry, where it is listed as “Internal Medicine”.
NPI registry
Where is Dr. Shields located?
Dr. Shields is listed at 24221 Calle de la Louisa Suite 200, Laguna Hills, CA 92653. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
What is Dr. Shields's phone number?
The number on file is (949) 588-8700. Contact the office directly to confirm availability and scheduling.
NPI registry
What is the NPI for Dr. Shields?
Dr. Shields's National Provider Identifier is 1366411555. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
Where did Dr. Shields go to medical school?
Dr. Shields attended University of California, Geffen School of Medicine, graduating in 1992. This comes from the CMS National Downloadable File.
CMS public data
How much experience does Dr. Shields have?
Dr. Shields has 34 years experience. Calculated from a graduation year of 1992, reported in the CMS National Downloadable File.
CMS public data
What does Dr. Shields do most often?
According to Medicare billing data, Dr. Shields performs procedures including insertion of needle into vein for collection of blood sample; provides treatments such as influenza vaccine, inactivated and routine electrocardiogram using at least 12 leads with interpretation and report, alongside routine visits and testing. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dr. Shields's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Shields. If this is you, claiming it is free.
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