CPC Formula Reference Cards — CodeCram
Quick-Reference Formula Cards

The formulas you need
in your head on exam day.

6 cards covering anesthesia calculations, E/M leveling, modifier rules, ICD-10 sequencing, and HCPCS. Study from your phone. Print it. Know it cold.

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Anesthesia Formula
B + T + M — the only math on the CPC exam
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Total Units = B + T + M
Base Units (procedure) + Time Units (15 min = 1 unit) + Modifying Units (physical status + qualifying circumstances)
Time Conversion
MinutesTime UnitsNotes
15 min1 unitStandard rate
30 min2 units
45 min3 units
60 min4 units1 hour
90 min6 units1.5 hours
120 min8 units2 hours
Physical Status Modifiers (add to M)
CodePatient StatusUnits Added
P1Normal healthy patient0
P2Mild systemic disease0
P3Severe systemic disease1
P4Life-threatening systemic disease2
P5Moribund patient (not expected to survive)3
P6Brain-dead, organ donor0 (not separately billable)
Qualifying Circumstances (CPT 99100–99140, add to M)
CodeCircumstanceUnits Added
99100Extreme age — patient <1 year or >70 years1
99116Complicated by utilization of total body hypothermia5
99135Complicated by controlled hypotension5
99140Emergency conditions (patient's life at risk)2
Worked Examples
Example 1 — Healthy adult, 45-minute procedure
Base = 7 units (per CPT code) · Time: 45 min = 3 units · Status: P1 = 0 · No QC
7 + 3 + 0 = 10 total units
Example 2 — Severe systemic disease, 60-minute procedure, emergency
Base = 5 units · Time: 60 min = 4 units · P3 = 1 unit · QC 99140 = 2 units
5 + 4 + (1 + 2) = 12 total units
Example 3 — Pediatric patient (<1 yr), 30-minute procedure
Base = 10 units · Time: 30 min = 2 units · P2 = 0 · QC 99100 = 1 unit
10 + 2 + (0 + 1) = 13 total units
Key rule: P1 and P2 add zero modifying units. P3+ start adding. Qualifying circumstances stack with physical status modifiers — add both to M.
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E/M Leveling Quick Reference
2021+ guidelines — MDM or Time, whichever supports higher level
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The key decision: Choose level by Medical Decision Making (MDM) or total time — whichever supports the higher level. History and exam no longer independently determine E/M level (2021+).
Code Ranges by Patient Type
Patient TypeLevel 1Level 2Level 3Level 4Level 5
New Patient 9920299202992039920499205
Established Pt 9921199212992139921499215
99201 was deleted in 2021. New patient range now starts at 99202 (was 99201–99205). Established patients: 99211 still exists (nurse visit, minimal MDM).
MDM Table (2021+ Framework)
MDM Level New/Est Code # of Dx / Mgmt Options Data Reviewed Risk of Complications
Straightforward 99202 / 99212 1 self-limited/minor problem Minimal or none Minimal risk
Low 99203 / 99213 2+ self-limited, or 1 stable chronic Limited (1 category) Low risk (OTC drugs, minor procedures)
Moderate 99204 / 99214 1+ chronic illness with exacerbation, or new undiagnosed problem Moderate (review external records, independent interpretation) Moderate risk (Rx drug management, minor surgery with risk)
High 99205 / 99215 1+ chronic illness with severe exacerbation, threat to life/function Extensive (independent historian, independent interpretation of tests) High risk (drug therapy requiring monitoring, major surgery with risk)
Time-Based Selection (Total Encounter Time)
CodeNew Patient TimeEstablished Time
99202 / 9921215–29 min10–19 min
99203 / 9921330–44 min20–29 min
99204 / 9921445–59 min30–39 min
99205 / 9921560–74 min40–54 min
Time includes: All medically appropriate time on the date of the encounter — before, during, and after. Does not require a specific % of counseling anymore (that rule is gone for office E/M).
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Modifier Decision Tree
If → Then format — know when to append which modifier
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Modifier 25 — Significant, Separately Identifiable E/M
IF
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E/M service is performed on the same day as a procedure AND the E/M is a significant, separately identifiable service above the usual pre/post-op care
THEN
→
Append -25 to the E/M code (not the procedure code)
NOTE
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The -25 goes on the E/M code, not the procedure. Separate documentation required for both services.
Modifier 59 — Distinct Procedural Service
IF
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Two procedures are normally bundled (same session, same provider) but are actually distinct services (different site, different session, different organ)
THEN
→
Append -59 to the second (lower-value) procedure to unbundle
TIP
→
-59 has 4 more specific sub-modifiers (X{EPSU}): XE (separate encounter), XS (separate structure), XP (separate practitioner), XU (unusual non-overlapping). Use X-modifiers when payer requires specificity.
Modifiers 26 / TC — Professional & Technical Components
IF
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Physician interprets a test/image but does not own/operate the equipment
THEN
→
Bill with -26 (Professional Component — physician's interpretation/report only)
IF
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Facility/hospital owns the equipment and provides technical service only (no physician interpretation)
THEN
→
Bill with -TC (Technical Component)
NOTE
→
No modifier = global service (physician owns equipment AND interprets). -26 + TC together = global.
Modifiers 76 / 77 — Repeat Procedures
76
→
Repeat procedure by the same physician on the same day — not an error, medically necessary repeat
77
→
Repeat procedure by a different physician on the same day
TRICK
→
76 = same doctor (76 looks like a V — V for reVisit by same). 77 = different doctor.
Modifier order matters for pricing: Price-affecting modifiers (51, 52, 53, 62, 66, 80) should precede informational modifiers (25, 59, 76, etc.) when appending multiple modifiers.
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ICD-10 Sequencing Rules
Principal diagnosis, Excludes notes, external causes, 7th characters
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Principal Diagnosis Selection
RULE
→
Principal diagnosis = the condition established after study to be chiefly responsible for the admission/encounter (not necessarily the most severe condition)
OUTPT
→
Outpatient: code the condition to the highest degree of certainty. If uncertain, code the sign/symptom — not the probable diagnosis.
INPT
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Inpatient: probable, suspected, possible conditions may be coded as if confirmed.
Excludes1 vs Excludes2
Note TypeMeaningCan Both Be Coded?
Excludes1 Pure exclude — the condition in the Excludes1 note is mutually exclusive. The two codes represent the same condition coded differently. NO — cannot code both (absolute exclusion)
Excludes2 Not included here — the excluded condition is not part of this code, but the patient may have both conditions simultaneously. YES — may code both if both are documented and present
Memory trick: Excludes1 = 1 code only (mutually exclusive). Excludes2 = can code 2 (both may apply).
External Cause Codes (V/W/X/Y codes)
RULE
→
External cause codes are never sequenced first. Always a secondary code — used to describe the cause of the injury.
ORDER
→
1st = injury/condition code → 2nd = external cause (how) → 3rd = place of occurrence (where) → 4th = activity code (what doing)
NOTE
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Place of occurrence (Y93._) and activity codes (Y99._) are one-time codes for the initial encounter only — not subsequent or sequela encounters.
7th Character Extensions
7th CharacterMeaningWhen to Use
A Initial encounter Active phase of treatment — patient is receiving active treatment for the injury/condition (even if seeing a new provider)
D Subsequent encounter After active phase — routine care, healing, recovery (e.g., cast change, medication adjustment after fracture healing)
S Sequela Late effects of a previous injury/condition — the residual condition after healing is complete
Critical distinction: A vs D is about active treatment, not how many times you've seen the patient. A patient at their 5th visit is still "A" if they're still in active treatment. Switch to "D" when moving to routine/maintenance care.
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HCPCS Level II Quick Reference
Code structure, J-codes, DME ranges, and when HCPCS overrides CPT
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Code Structure Comparison
SystemFormatExampleMaintained By
HCPCS Level I (= CPT) 5 numeric digits 99214, 27447 AMA
HCPCS Level II 1 letter + 4 digits J0696, E0143, G0101 CMS (not AMA)
Common Code Letter Ranges
LetterCategoryExample
AAmbulance, medical/surgical supplies, administrative/miscA0430 (ambulance air)
BEnteral/parenteral therapyB4150 (enteral formula)
EDurable Medical Equipment (DME)E0143 (walker), E0601
GTemporary codes for CMS services (Medicare)G0101 (cervical cancer screening), G0008 (flu vaccine admin)
JDrugs administered other than oral (injections)J0696 (cefazolin), J1745 (infliximab)
KTemporary codes for DME/supplies not yet in HCPCSK0001 (standard wheelchair)
LOrthotic/prosthetic proceduresL0130 (cervical orthosis)
QTemporary codes — miscellaneousQZ (CRNA independent), QK (medical direction)
SPrivate payer codes (NOT covered by Medicare)S0010–S9999
VVision, hearing, and speech servicesV2100 (sphere lens)
When HCPCS Level II Overrides CPT
IF
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The payer is Medicare or Medicaid and a HCPCS Level II code exists for the service
THEN
→
Use the HCPCS Level II code instead of the CPT code — HCPCS supersedes CPT for federal payers
NOTE
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Commercial payers may accept CPT. Always check payer guidelines. J-codes are required for drug billing regardless of payer when the drug has a J-code.
DME
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DME (E-codes) must always use HCPCS Level II for Medicare. CPT has no equivalent DME codes.
J-code unit calculation: J-codes are per unit of drug (e.g., per 50 mg). Always divide the dosage administered by the per-unit amount in the code descriptor to get the number of units to bill.
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High-Yield Rules Cheat Sheet
The rules that trip people up — know these cold
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Surgery / CPT Coding Rules
GLOBAL
→
Global surgery package includes: pre-op (day before), intra-op, and post-op care (10 or 90 days depending on major/minor). Normal post-op visits are NOT separately billable.
UNBUND
→
Unbundling = separately billing components of a bundled code. This is fraudulent. Use modifier -59 ONLY when services are truly distinct.
ADD-ON
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Add-on codes (marked with +) can never be reported alone. They always require a primary procedure code from an approved list.
BILAT
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Bilateral procedures: if no bilateral code exists, report the unilateral code twice with modifier -50. Some payers want one line with -50; others want two lines with -RT/-LT.
Compliance & Audit Traps
STARK
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Stark Law = strict liability — no intent required. A physician cannot self-refer for designated health services. Civil penalties only (not criminal).
AKS
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Anti-Kickback Statute = intent required. Knowingly offering/receiving anything of value to induce referrals. Criminal penalties (jail + fines).
ABN
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Advance Beneficiary Notice — must be issued before providing a service Medicare may not cover. Without it, provider cannot bill the patient. Modifier -GA = ABN on file.
FRAUD
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Upcoding, unbundling, billing non-covered services as covered — all constitute fraud. Can result in exclusion from Medicare (OIG Exclusion List), civil monetary penalties, and criminal charges.
ICD-10 High-Yield Rules
CODE1ST
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"Code first" instruction = sequence the underlying condition before the manifestation code (even if manifestation drove the visit).
USE ADD
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"Use additional code" = you MUST add a secondary code to provide further detail. Reporting only the primary code is incomplete.
SIGNS
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Signs & symptoms are not coded separately when they are integral to a confirmed diagnosis. Code only the confirmed diagnosis.
CPC exam tip: When you see "principal diagnosis" — that's always the reason established after study, not the admitting complaint. When you see a compliance question, look for the intent distinction: Stark = no intent needed, AKS = intent required.
📋 Also read: Exam Day Prep Guide
Timing strategy, 4-pass method, what to bring, and proctor anxiety tactics
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