Q85.81 PTEN hamartoma tumor syndrome

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis. Exempt from present-on-admission (POA) reporting.

Applicable to

• PHTS
• PTEN related Cowden syndrome

Code also

• , if applicable, genetic susceptibility to malignant neoplasm (Z15.0-)

Applies from Q85 Phakomatoses, not elsewhere classified

Excludes1 (never code together)

• ataxia telangiectasia [Louis-Bar] (G11.3)
• familial dysautonomia [Riley-Day] (G90.1)

Applies from Q85.8 Other phakomatoses, not elsewhere classified

Excludes1 (never code together)

• Meckel-Gruber syndrome (Q61.9)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 23 — Prostate, Breast, and Other Cancers and Tumors
• CMS-HCC V22: HCC 12 — Breast, Prostate, and Other Cancers and Tumors
• RxHCC V08: HCC 22 — Prostate, Breast, Bladder, and Other Cancers and Tumors
• ESRD V24: HCC 12

MS-DRG index

Defines the logic of DRG(s) 826-828 in MDC 17.

Diagnosis Index entries for Q85.81

• PHTS
• Syndrome › Cowden › PTEN related
• Syndrome › PTEN (hamartoma) tumor

Nearby codes

• Q85.02 Neurofibromatosis, type 2
• Q85.03 Schwannomatosis
• Q85.09 Other neurofibromatosis
• Q85.1 Tuberous sclerosis
• Q85.8 Other phakomatoses, not elsewhere classified
• Q85.81 PTEN hamartoma tumor syndrome (this code)
• Q85.82 Other Cowden syndrome
• Q85.83 Von Hippel-Lindau syndrome
• Q85.89 Other phakomatoses, not elsewhere classified
• Q85.9 Phakomatosis, unspecified