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B59

Billable

Pneumocystosis

HCC Category Mapping

V28HCC 6Opportunistic Infections
0.439
V24HCC 6Opportunistic Infections
0.440
ESRDHCC 6Opportunistic Infections
0.000
RxHCCHCC 5Opportunistic Infections
0.000

What This Code Means

A serious lung infection caused by Pneumocystis, a fungal organism, that primarily affects people with weakened immune systems.

Coding Tips

  • This diagnosis is commonly associated with HIV/AIDS; verify and code the underlying immunocompromised condition
  • Specify the type of pneumonia (PCP) and whether it is the initial diagnosis or recurrent

Clinical Significance

Pneumocystosis (Pneumocystis jirovecii pneumonia, formerly called PCP) is one of the most common and best-recognized AIDS-defining opportunistic infections. It remains the most frequent cause of respiratory failure in untreated HIV patients with CD4 counts below 200. Despite effective prophylaxis, it continues to occur in undiagnosed HIV patients and those non-adherent to treatment, carrying 10-20% mortality even with appropriate therapy.

Documentation Requirements

  • Bronchoalveolar lavage or induced sputum with positive Pneumocystis jirovecii stain (GMS, DFA, or PCR)
  • Chest imaging showing bilateral ground-glass opacities (classic pattern)
  • Arterial blood gas or pulse oximetry showing hypoxemia
  • CD4 count documented (typically <200 cells/microL) and HIV status
  • Treatment documented: trimethoprim-sulfamethoxazole for 21 days, adjunctive corticosteroids if PaO2 <70
  • LDH level (typically elevated; useful for prognostication)

Commonly Confused Codes

Code Hierarchy

B59Pneumocystosis
B59Pneumocystosis

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