Medical Coding Mnemonics: 12 Memory Tricks for the CPC Exam

Steps to assign an ICD-10-CM code

“Code it RITE”

1. RRead the record and pick the main term: the condition, not the body part
2. IIndex: look it up in the Alphabetic Index, following subterms and see/see also notes
3. TTabular: verify the code and read every note (Includes, Excludes, code first, use additional)
4. EEvery character: code to the highest specificity, add the 7th character and X placeholders

Use it when: On every diagnosis question, and especially when two options differ only in the 4th to 7th character.

Careful: Never code from the Index alone. In outpatient settings do not code 'probable', 'suspected' or 'rule out' diagnoses; code the signs and symptoms (Section IV.H). Inpatient rules are the opposite (Section II.H), and the exam tests the difference.

Excludes1 versus Excludes2

“Excludes1: never together. Excludes2: can be together too.”

Excludes1 is a pure exclusion: the two conditions cannot occur together (for example a congenital and an acquired form), so the excluded code is never reported with this one. Excludes2 means 'not included here': the excluded condition is not part of this code, but the patient can have both, so both may be reported.

Use it when: When an option pairs two codes and you need to know whether the Tabular allows them on the same claim.

Careful: The guidelines (I.A.12.a) allow an exception to Excludes1 when the two conditions are unrelated to each other; in that case both may be coded. Excludes notes are read at the code, category and chapter level.

Etiology and manifestation sequencing

“Cause before effect”

When a condition has an underlying cause and a manifestation in another body system, the etiology is sequenced first and the manifestation second. The Tabular signals this with 'use additional code' at the etiology and 'code first' at the manifestation; manifestation codes appear in italics in the Tabular and in brackets in the Index.

Use it when: When a stem gives a disease plus its complication (for example dementia in Parkinson disease) and the options differ in order.

Careful: Codes titled 'in diseases classified elsewhere' are never first-listed. A 'code also' note does not set the order. Chapter-specific rules can override this, such as B20 first for HIV-related conditions.

Injury 7th characters

“A-D-S: Active, Doing better, Sequela”

1. AInitial encounter: the patient is receiving active treatment
2. DSubsequent encounter: routine care in the healing or recovery phase
3. SSequela: a late effect or residual of the injury

Use it when: When options differ only in the 7th character of an injury, poisoning or fracture code.

Careful: A means active treatment, not 'first visit': a new physician treating the injury actively still uses A. For sequelae, code the residual condition first and the injury code with S second. Fracture codes add more values (for example G, K, P for delayed healing, nonunion, malunion).

Modifier 25 versus 57

“25 for minor, 57 for major”

Modifier 25 goes on a significant, separately identifiable E/M service on the same day as a procedure, typically a minor procedure (0 or 10-day global). Modifier 57 goes on the E/M at which the decision for major surgery (90-day global) is made, on the day before or the day of surgery.

Use it when: When a patient is seen and has a procedure the same day, or the decision to operate is made at the visit.

Careful: Under CMS rules the decision to perform a minor procedure is included in that procedure's payment, so 25 needs work beyond the usual pre-procedure assessment. Both modifiers go on the E/M code, never on the procedure.

The X{EPSU} modifiers and 59

“Every Patient Should Understand”

1. XESeparate Encounter: a different session on the same date
2. XPSeparate Practitioner: performed by a different practitioner
3. XSSeparate Structure: a different organ or structure
4. XUUnusual non-overlapping service: does not overlap the usual parts of the main service

Use it when: When an NCCI edit bundles two procedures that were in fact distinct and you must choose how to report it.

Careful: 59 is the modifier of last resort: use it only when no more descriptive modifier fits, and never on an E/M code (that is 25). The X modifiers are more specific subsets of 59; do not report both 59 and an X modifier on the same line.

Repeat and postoperative-period modifiers

“76 me again, 77 someone else; 78 back to the OR, 79 something new”

1. 76Repeat procedure or service by the same physician or QHP
2. 77Repeat procedure by another physician or QHP
3. 78Unplanned return to the OR for a related procedure during the postop period
4. 79Unrelated procedure by the same physician during the postop period

Use it when: When a stem has a second procedure on the same day or inside a global period and asks which modifier fits.

Careful: Planned or staged procedures, or ones more extensive than the original, take 58, not 78. 58 and 79 start a new global period; 78 does not. 76 and 77 are for procedures, not E/M visits.

Multiple and bilateral procedures

“Add-ons never take 51”

List the highest-valued procedure first and append 51 to additional procedures by the same physician in the same session. Add-on codes (marked +) and codes listed as 51-exempt are never given 51 because their value already assumes they go with a primary code. Modifier 50 is for a procedure done on both sides when the descriptor describes one side.

Use it when: When options differ by 51 or 50, or when an add-on code such as 22614 or 11045 appears in the code set.

Careful: Do not use 50 when the descriptor already says bilateral or 'unilateral or bilateral' (for example 61000). Payers differ: Medicare applies the multiple-procedure reduction itself and wants a bilateral procedure on one line with 50 and 1 unit.

Medical decision making elements

“PDR: two out of three wins”

1. PProblems: number and complexity of problems addressed
2. DData: amount and complexity of data reviewed and analyzed (tests, notes, independent historian, interpretation, discussion)
3. RRisk: risk of complications, morbidity or mortality of patient management

Use it when: When a visit note gives problems, data and management and you must pick the MDM level and then the code.

Careful: Two of the three elements must meet or exceed a level; you do not average them. History and exam no longer set the level (they must only be medically appropriate), and the level can be chosen by total time on the date instead if that is more favorable.

New versus established patient

“Three years, same specialty, same group”

A patient is established if they received any professional face-to-face service from the physician or QHP, or from another of the exact same specialty and subspecialty in the same group practice, within the past three years. Otherwise they are new.

Use it when: When a stem gives a visit history and the options mix 9920x (new) and 9921x (established) codes.

Careful: A different subspecialty in the same group makes the patient new to that provider. A physician covering for a colleague classifies the patient as the absent physician would have. An NP or PA counts as the same specialty as the physicians they work with.

Global surgical package (CMS)

“1 + 1 + 90”

For a major procedure (090 global), the package runs from the day before surgery, through the day of surgery, to 90 days after. It includes pre-op visits after the decision for surgery, the procedure, complications that do not need a return to the OR, routine post-op visits, post-op pain management by the surgeon, and services such as dressing changes and suture or staple removal. Minor procedures have a 000 or 010 global with the day of the procedure included.

Use it when: When a stem asks whether a post-op visit or service is separately billable, or which modifier unbundles it.

Careful: Outside the package: the visit where the decision for major surgery is made (57), unrelated E/M in the post-op period (24), a return to the OR for complications (78), and unrelated procedures (79). CPT's own surgical package does not include complications; CMS's does unless the patient returns to the OR.

HCPCS Level II sections

“J is for Jab, E for Equipment, L for Limbs, B for Bottle”

1. AAmbulance and medical/surgical supplies
2. BEnteral and parenteral therapy (the feeding bottle)
3. EDurable medical equipment
4. GTemporary professional procedures and services (e.g. Medicare education services)
5. JDrugs administered other than orally, and chemotherapy drugs
6. LOrthotics and prosthetics
7. VVision, hearing and speech-language services

Use it when: When you need to jump to the right HCPCS section for a supply, drug or Medicare service before searching the index.

Careful: J-code units are the dose given divided by the amount in the descriptor, rounded up to a whole unit (J3301 is per 10 mg, so 40 mg is 4 units). Use the HCPCS index first; a few oral drugs (for example some anticancer and antiemetic drugs) also sit in J.