Key Takeaways
- The Medicine section (90281-99607) covers a broad range of non-surgical services including immunizations, injections/infusions, cardiovascular procedures, allergy testing, and ophthalmology.
- Vaccine coding requires two codes: the vaccine product code (90460-90749) AND the administration code (90460-90461 or 90471-90474) — never report just the product alone.
- Infusion/injection coding (96360-96379) follows hierarchy rules: chemotherapy infusions take precedence over therapeutic infusions, which take precedence over hydration.
- The anesthesia coding formula is: Total Anesthesia Value = Base Units (B) + Time Units (T) + Modifying Units (M), multiplied by the conversion factor.
- Anesthesia time begins when the anesthesiologist begins preparing the patient for anesthesia and ends when the patient is released to postoperative care.
- Physical status modifiers (P1-P6) describe the patient's health status and affect anesthesia payment, ranging from P1 (normal healthy patient) to P6 (declared brain-dead patient).
- Qualifying circumstances codes (99100, 99116, 99135, 99140) are add-on codes for situations that increase anesthesia complexity (extreme age, hypothermia, controlled hypotension, emergency).
- The Medicine section includes many add-on and exempt-from-modifier-51 codes that must be identified to avoid incorrect modifier application.
Medicine Section & Anesthesia Coding
The Medicine section of CPT is one of the most diverse, covering services that do not fit neatly into the E/M or Surgery sections. Anesthesia coding has its own unique formula and modifier system. Together, these sections account for approximately 15-20% of CPC exam questions.
Medicine Section (90281-99607)
Key Medicine Subsections
| Subsection | Code Range | Examples |
|---|---|---|
| Immune Globulins | 90281-90399 | Hepatitis B immune globulin, RhoGAM |
| Immunization Administration | 90460-90474 | Injection, oral, intranasal vaccine administration |
| Vaccines/Toxoids | 90476-90749 | Influenza, pneumococcal, COVID-19 vaccines |
| Hydration/Infusions | 96360-96379 | IV hydration, therapeutic infusions, chemotherapy |
| Cardiovascular | 93000-93998 | EKGs, echocardiograms, cardiac catheterization |
| Pulmonary | 94002-94799 | Spirometry, pulmonary function tests |
| Allergy/Immunology | 95004-95199 | Allergy testing, immunotherapy injections |
| Neurology | 95700-95999 | EEGs, EMGs, nerve conduction studies |
| Ophthalmology | 92002-92499 | Eye exams, visual field testing |
| Physical Medicine | 97010-97799 | Physical therapy modalities and procedures |
| Chiropractic | 98940-98943 | Chiropractic manipulative treatment |
Vaccine/Immunization Coding
Vaccine coding always requires two codes:
1. Vaccine Product Code (What was given)
| Example | Code | Description |
|---|---|---|
| Influenza vaccine | 90688 | Influenza virus vaccine, quadrivalent |
| Pneumococcal vaccine | 90670 | Pneumococcal conjugate vaccine, 13 valent |
| Hepatitis B vaccine | 90746 | Hepatitis B vaccine, adult dosage |
2. Administration Code (How it was given)
For patients through 18 years (with counseling):
| Code | Description |
|---|---|
| 90460 | Immunization administration through 18 years, first vaccine/toxoid component, with counseling |
| 90461 | Each additional vaccine/toxoid component (add-on to 90460) |
For patients over 18 (or without counseling):
| Code | Description |
|---|---|
| 90471 | Immunization administration, first vaccine, percutaneous/intradermal/subcutaneous/intramuscular |
| 90472 | Each additional vaccine (add-on to 90471) |
| 90473 | Immunization administration, first vaccine, intranasal or oral |
| 90474 | Each additional vaccine, intranasal or oral (add-on to 90473) |
Example: An adult receives an influenza vaccine (IM injection) and a pneumococcal vaccine (IM injection) at the same visit:
- 90688 (influenza vaccine product)
- 90670 (pneumococcal vaccine product)
- 90471 (administration, first vaccine — injection)
- 90472 (administration, each additional vaccine — injection)
Infusion/Injection Hierarchy (96360-96379)
When multiple IV services are provided on the same day, coding follows a strict hierarchy:
Hierarchy (Highest to Lowest Priority)
| Priority | Service Type | Initial Code | Additional Hour | Push |
|---|---|---|---|---|
| 1 (Highest) | Chemotherapy infusion | 96413 | +96415 | 96409 |
| 2 | Therapeutic infusion | 96365 | +96366 | 96374 |
| 3 (Lowest) | Hydration | 96360 | +96361 | N/A |
Infusion Coding Rules
- Only ONE initial service code per encounter — from the highest hierarchy category
- Concurrent infusions (two substances at the same time through same IV or different IV) use the concurrent add-on code
- Sequential infusions (one after another through the same IV access) use the sequential add-on code
- Different substances via the same access site at different times are sequential
- Hydration performed at the same time as a therapeutic/chemo infusion is NOT separately reportable
- Minimum time: Initial infusion codes require at least 16 minutes of infusion time; additional hour codes require at least 31 minutes beyond the initial hour
Anesthesia Coding (00100-01999)
The Anesthesia Formula
Anesthesia payment is calculated using:
Total Anesthesia Allowance = (Base Units + Time Units + Modifying Units) x Conversion Factor
| Component | Definition | How Determined |
|---|---|---|
| Base Units (B) | Reflects the complexity of the anesthesia service | Assigned to each anesthesia code by the ASA Relative Value Guide |
| Time Units (T) | Duration of anesthesia | Calculated based on actual anesthesia time (typically 1 unit per 15 minutes) |
| Modifying Units (M) | Additional complexity factors | Physical status modifiers, qualifying circumstances |
| Conversion Factor | Dollar value per unit | Varies by payer and geographic location |
Anesthesia Time
- Starts: When the anesthesiologist begins preparing the patient for anesthesia induction
- Ends: When the anesthesiologist releases the patient to postoperative care (e.g., PACU nurse)
- Includes: Pre-anesthesia preparation, induction, maintenance, emergence, and immediate post-anesthesia care
- Conversion: Most commonly, 1 time unit = 15 minutes (varies by payer)
Example Calculation:
- Procedure: Anesthesia for total knee replacement
- Base units: 7
- Anesthesia time: 90 minutes = 6 time units (90 / 15)
- Physical status: P2 (mild systemic disease) = 0 additional units
- Total units: 7 + 6 + 0 = 13 units
- If conversion factor = $22.00 per unit → $286.00
Physical Status Modifiers (P1-P6)
Physical status modifiers are appended to the anesthesia code and describe the patient's overall health:
| Modifier | Description | Additional Units (Typical) |
|---|---|---|
| P1 | Normal healthy patient | 0 |
| P2 | Patient with mild systemic disease | 0 |
| P3 | Patient with severe systemic disease | 1 |
| P4 | Patient with severe systemic disease that is a constant threat to life | 2 |
| P5 | Moribund patient not expected to survive without the operation | 3 |
| P6 | Declared brain-dead patient (organ donor) | 0 |
Qualifying Circumstances (Add-On Codes)
These codes are reported IN ADDITION to the anesthesia code when specific high-risk conditions exist:
| Code | Circumstance | Additional Units |
|---|---|---|
| 99100 | Anesthesia for patient of extreme age (under 1 year or over 70 years) | Varies by payer |
| 99116 | Anesthesia complicated by utilization of total body hypothermia | Varies |
| 99135 | Anesthesia complicated by utilization of controlled hypotension | Varies |
| 99140 | Anesthesia for emergency conditions | Varies |
Cardiovascular Medicine Codes
Common Cardiovascular Studies
| Study | Code | Components |
|---|---|---|
| 12-lead ECG | 93000 (global) | Tracing + interpretation + report |
| ECG tracing only | 93005 | Technical component |
| ECG interpretation only | 93010 | Professional component |
| Transthoracic echo (TTE) | 93306 | Complete TTE with Doppler |
| Holter monitor | 93224-93227 | Recording + analysis + interpretation |
| Stress test | 93015-93018 | May be split into components |
An adult patient receives an influenza vaccine (IM) and a Tdap vaccine (IM) at the same office visit. How many CPT codes are reported in total?
A patient receives IV hydration for 45 minutes, followed by a therapeutic IV infusion of an antibiotic for 1 hour and 20 minutes. Using the infusion hierarchy, what is the initial service?
What is the anesthesia formula used to calculate anesthesia reimbursement?
Anesthesia time begins when the anesthesiologist starts preparing the patient and ends when the patient is released to _____ care.
Type your answer below
Match each anesthesia physical status modifier to its description:
Match each item on the left with the correct item on the right
A qualifying circumstances code (99100) is reported when anesthesia is provided to which type of patient?
Arrange the infusion hierarchy from HIGHEST priority to LOWEST priority:
Arrange the items in the correct order