TOP ICD-10-CM CODES (memorise these):
  E11.9   Type 2 DM, no complications
  E11.65  Type 2 DM with hyperglycemia
  I10     Essential (primary) hypertension
  I50.9   Heart failure, unspecified
  I50.23  Acute-on-chronic systolic CHF
  J18.9   Pneumonia, unspecified organism
  J44.1   COPD with acute exacerbation
  N18.3   CKD stage 3
  M79.3   Panniculitis (unspecified)
  Z00.00  Encounter for general adult medical exam
  Z12.11  Encounter for screening for malignant neoplasm of colon
  Z79.4   Long-term (current) use of insulin
  Z87.891 Personal history of nicotine dependence

TOP CPT E&M CODES:
  99213   Office/outpatient established, low complexity
  99214   Office/outpatient established, moderate complexity
  99215   Office/outpatient established, high complexity
  99203   Office/outpatient new, low complexity
  99204   Office/outpatient new, moderate complexity
  99232   Hospital subsequent, moderate complexity
  99283   Emergency dept, moderate complexity
  99291   Critical care, first 30-74 minutes

TOP MODIFIERS:
  -22  Increased procedural services
  -25  Significant, separate E&M same day as procedure
  -26  Professional component only
  -50  Bilateral procedure
  -51  Multiple procedures
  -59  Distinct procedural service
  -76  Repeat procedure same physician
  -TC  Technical component only
  -LT/-RT  Left/Right side

CODE SEQUENCING:
  Inpatient: principal diagnosis first (condition after study that occasioned admission)
  Outpatient: first-listed diagnosis (condition chiefly responsible for the visit)
  
CODE TO HIGHEST SPECIFICITY:
  Wrong: E11.9 (unspecified) when documentation says "with neuropathy"
  Right: E11.40 (Type 2 DM with diabetic neuropathy, unspecified)
  
UNCERTAIN DIAGNOSES:
  Inpatient: code probable/suspected/likely as confirmed
  Outpatient: code symptoms only (NOT probable/suspected/rule out)
  
COMBINATION CODES:
  Use single combination code when available (E11.65 = DM2 + hyperglycemia)
  Do not code two codes if one combination code covers both conditions
  
SIGNS AND SYMPTOMS:
  Code as additional: if not routinely associated with confirmed diagnosis
  Do NOT code: if integral to confirmed diagnosis (cough with COPD = don't separately code)