2026 ICD-10-CM Diagnosis Code R85.610Atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US)

ICD-10-CM Codes›R00–R99›R83-R89›R85

ICD-10-CM R85.610
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R85.610 is a billable ICD-10-CM diagnosis code for atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US). It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as abnormal anal Papanicolaou smear. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.

Code Identity

ICD-10-CM Code
R85.610
Billable Status
Yes — Valid for Submission
Code Describes
Atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US)
Short Description
Atyp squam cell of undet signfc cyto smr anus (ASC-US)
Parent Code
R85.61
Abnormal cytologic smear of anus

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR83-R89Abnormal findings on examination of other body fluids, substances and tissues, without diagnosis
CategoryR85Abnormal findings in specimens from digestive organs and abdominal cavity
This CodeR85.610Atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US)

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal anal Papanicolaou smear
  • Atypical squamous cells of undetermined significance on anal Papanicolaou smear

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Abnormal, abnormality, abnormalities
      • cytology
        • anus
          • atypical squamous cells of undetermined significance (ASC-US)
    • Abnormal, abnormality, abnormalities
      • Papanicolaou (smear)
        • anus
          • atypical squamous cells of undetermined significance (ASC-US)
    • ASC-US(atypical squamous cells of undetermined significance on cytologic smear)
      • anus

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR SYM017
Abnormal findings without diagnosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert R85.610 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
796.71 Pap smear anus w ASC-US
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R85.610Overview

Is R85.610 (Abnormal cytologic smear of anus) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US) on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R85.610 group to?

When atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US) is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, with relative weights from 0.6490 to 1.5993 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R85.610 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US) is established, that condition takes the principal position instead.

What is the ICD-9 equivalent of R85.610?

Under the General Equivalence Mappings, atypical squamous cells of undetermined significance on cytologic smear of anus (ASC-US) converts to ICD-9-CM 796.71 (pap smear anus w ASC-US). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.