Provider Profile
Spencer J. Mares, FNP-C, AGACNP-BC
Unclaimed ProfileAbout Spencer Mares
Listed in the NPI registry as a nurse practitioner — acute care, Spencer J. Mares, FNP-C, AGACNP-BC practices in Lake Saint Louis, MO. Spencer is also listed as specializing in nurse practitioner — family. According to Medicare claims data, Spencer cared for 339 Medicare patients across 359 services. The services billed most often include initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes, advance care planning, first 30 minutes, and critical care, first 30-74 minutes.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
Education & Training
Specialty
Credentials & Licensing
License numbers are what the provider reported to NPPES when the NPI was issued or updated. NPPES does not verify licensure; confirm current standing with the state licensing board.
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
- (636) 625-5200
- Email not available
Practice Locations
100 MEDICAL PLZ
Lake Saint Louis, MO 63367
Conditions and Services Within This Provider's Scope
Within Nurse Practitioner - Acute Care 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
Allergic reactions
- Severe Allergic Reaction
Brain & Nerve
- Concussion in Children
- Delirium
- Ischemic stroke
- Transient ischemic attack
Brain & nerves
- Status epilepticus
Digestive & Abdominal
- Abdominal Pain
- Acute gallbladder inflammation
- Acute pancreatitis
- Ascites
- Internal Bleeding
- Small-bowel obstruction
Digestive issues
- Appendicitis
- Perforated gastrointestinal tract
- Severe diverticulitis flare-up
Emergency care
- Drug overdose or poisoning
General Acute Care
- Severe dehydration
Heart & Circulation
- AFib
- Dangerous high blood pressure
- Deep vein thrombosis
- Heart attack
- Heart failure flare-up
- Shock
- Unexplained chest pain
Heart & circulation
- Aortic aneurysm
- Infective endocarditis
- Pericarditis
- Slow heart rate (bradycardia)
Hormone & Metabolism
- Dangerous high blood sugar
- Low sodium or electrolyte imbalance
Infections
- Bone infection
- C. diff Infection
- Cellulitis
- Community-acquired pneumonia
- Kidney infection
- Meningitis
- Sepsis or blood infection
Kidney & Urinary
- Acute kidney injury
Liver & kidney
- Sudden Liver Failure
Lung & Breathing
- Blood Clot in Lung
- Collapsed lung
- COPD flare-up
- Fluid around the lungs
- Low oxygen levels
- Respiratory failure
- Severe asthma attack
- Shortness of breath
Post-Surgery Care
- Post-surgery fever or infection
Surgical recovery
- Paralyzed bowel after surgery
- Surgical wound opening
Trauma & injury
- Broken ribs
- Skull Fracture
Procedures & services
Blood & Infusion
- Blood Transfusion Management
Bones & Joints
- Joint injection or aspiration
- Splinting for Fractures
Brain & Nerve
- Lumbar puncture
Brain & nerve care
- Brain pressure monitoring
Breathing & lung support
- Breathing tube removal
- Chest Needle Decompression
- Chest tube removal
- CPAP titration
Critical care
- Continuous dialysis for children
- ICU sedation and awakening trials
Critical Care Procedures
- Arterial catheter placement
- Central line placement
- Critical Care Consultation
- Emergency intubation
- Sepsis Treatment Protocol
Digestive & Abdominal
- Feeding or stomach tube insertion
- Paracentesis
Emergency care
- Emergency epinephrine injection
- Emergency trauma evaluation
- Rapid response team evaluation
- Stomach pumping or activated charcoal
Follow-up & recovery
- Post-ICU recovery visit
General Acute Care
- Comfort Care Management
- Hospital Discharge Follow-Up
Heart & Circulation
- Electrical cardioversion
- Heart Rhythm Monitoring
- Temporary Pacemaker Care
Kidney & Urinary
- Dialysis Catheter Care
- Urinary catheter insertion
Lung & Chest
- Breathing machine management
- Chest tube insertion
- Draining lung fluid
- Trach Tube Care and Changing
Medications & Monitoring
- Blood Clot Management
- IV Antibiotic Therapy
- IV electrolyte replacement
- IV Medication Management
Pain management
- Nerve Block Injection
Pain Management
- Patient-Controlled Analgesia (PCA) Setup
Post-Surgery Care
- Post-Surgery Follow-Up
Pre-Surgery
- Pre-surgery medical clearance
Surgical recovery
- Post-op drain removal
Testing & Monitoring
- Blood Gas Testing
- Emergency ultrasound
Vascular access
- Chemo port removal
- PICC line care and removal
Wound & Injury
- Burn dressing and care
- Incision and drainage of an abscess
- Surgical Wound Care
- Suture removal
Wound & injury care
- Dead tissue removal from wounds
- Minor laceration repair
- Superficial foreign-body removal
- Wound vacuum therapy
Procedures Most Often Billed to Medicare
359 services · 339 patients · 4 distinct codes
| Procedure | Type | Code | Services | Compared with peers |
|---|---|---|---|---|
| Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | Office visit | 99223 |
194 | More than most peers in Nurse Practitioner — Acute Care |
| Advance care planning, first 30 minutes | Office visit | 99497 |
72 | More often than most peers in Nurse Practitioner — Acute Care |
| Critical care, first 30-74 minutes | Office visit | 99291 |
63 | More often than most peers in Nurse Practitioner — Acute Care |
| Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes | Office visit | 99222 |
30 | As often as other peers in Nurse Practitioner — Acute Care |
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.
Related specialists at this location 3
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.
Trained at Other 8
Other providers in the same specialty who trained at the same institution.
More connections — 8 related providers in 1 group
Class of 2017 at Other 8
Providers who graduated from the same medical school in the same year.
Common questions
What kind of doctor is Spencer J. Mares, FNP-C?
Spencer J. Mares, FNP-C is a nurse practitioner in Lake Saint Louis, MO. That is the designation recorded for this NPI in the federal registry, where it is listed as “Nurse Practitioner — Acute Care”.
NPI registry
What is Spencer J. Mares, FNP-C's address?
Spencer J. Mares, FNP-C is listed at 100 Medical Plz, Lake Saint Louis, MO 63367. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How can I make an appointment with Spencer J. Mares, FNP-C?
The number on file is (636) 625-5200. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is Spencer J. Mares, FNP-C's NPI number?
Spencer J. Mares, FNP-C's National Provider Identifier is 1437667490. 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 Spencer J. Mares, FNP-C train?
Spencer J. Mares, FNP-C attended Other, graduating in 2017. This comes from the CMS National Downloadable File.
CMS public data
How long has Spencer J. Mares, FNP-C been practicing?
Spencer J. Mares, FNP-C has 9 years experience. Calculated from a graduation year of 2017, reported in the CMS National Downloadable File.
CMS public data
What procedures does Spencer J. Mares, FNP-C perform?
According to Medicare billing data, Spencer J. Mares, FNP-C the Medicare record under this individual NPI shows mainly office visits and diagnostic testing. Hospital-based physicians usually have their procedural work billed by the facility rather than under their own number, so this is a floor on their practice, not a description of it. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Has Spencer J. Mares, FNP-C confirmed this information?
Not yet. This profile is built from public federal data and has not been confirmed by Spencer J. Mares, FNP-C. If this is you, claiming it is free.
Guide.md
Provider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.