Gram Stain Organism Lookup
Search by organism name or ICD-10 code. Find Gram classification, morphology, and coding guidance from culture results.
How Gram Stain Affects ICD-10 Coding
Gram-Positive (+)
Cell wall retains crystal violet dye → stains purple under microscope. Most B95 codes (Staph, Strep, Enterococcus) are Gram-positive. Key sepsis codes: A41.01 (MRSA sepsis), A41.02 (MSSA sepsis), A41.0 (Staph sepsis).
Gram-Negative (−)
Thin cell wall does not retain dye → stains pink/red. Most B96 codes are Gram-negative. Sepsis from Gram-negative organisms → A41.5x range. Gram-negative bacteria are generally harder to treat — document organism specifically when culture is available.
Atypical / No Cell Wall
Organisms like Mycoplasma and Chlamydia lack a peptidoglycan cell wall — they don't Gram stain. Coded separately (B96.0 for Mycoplasma pneumoniae). Spirochetes (Borrelia, Treponema) stain poorly and are considered Gram-negative by convention.
Anaerobes
Can be Gram+ or Gram−. Bacteroides fragilis (B96.6) is Gram-negative anaerobic — common in abdominal/pelvic infections. Clostridium perfringens (B96.7) is Gram-positive anaerobic — gas gangrene, necrotizing fasciitis. Document "anaerobic" in the culture result for specificity.