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ICD-10-CM 2027 diagnosis code

Z45.321Encounter for adjustment and management of cochlear device

✓ Billable / specificPOA exempt

Z45.321 is a valid, billable ICD-10-CM code for encounter for adjustment and management of cochlear device. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Z45.321

Z45.321 is the ICD-10-CM diagnosis code for encounter for adjustment and management of cochlear device. It belongs to category Z45 (encounter for adjustment and management of implanted device), block Z40-Z53 (Encounters for other specific health care) and chapter 21 (factors influencing health status and contact with health services). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Z45.32 (encounter for adjustment and management of implanted hearing device), Z45.321 is specifically for encounter for adjustment and management of cochlear device. Related codes cover bone conduction device (Z45.320) and other implanted hearing device (Z45.328).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 154 (Other Ear, Nose, Mouth and Throat Diagnoses with MCC, relative weight 1.5921), DRG 155 (Other Ear, Nose, Mouth and Throat Diagnoses with CC, relative weight 0.9322) and DRG 156 (Other Ear, Nose, Mouth and Throat Diagnoses without CC/MCC, relative weight 0.6659), in MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as V53.09 (fitting and adjustment of other devices related to nervous system and special senses).

Notes that apply from higher levels

Instructions written at a parent level also apply to Z45.321.

› From Z45.32 Encounter for adjustment and management of implanted hearing device
Excludes1
  • Encounter for fitting and adjustment of hearing aid (Z46.1)
› From Z45 Encounter for adjustment and management of implanted device
Includes
  • removal or replacement of implanted device
Excludes1
  • malfunction or other complications of device - see Alphabetical Index
Excludes2
  • encounter for fitting and adjustment of non-implanted device (Z46.-)

Broader instructions also apply from Z40-Z53 Encounters for other specific health care and Chapter 21: Factors influencing health status and contact with health services.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to Z45.321.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • V53.09Fitting and adjustment of other devices related to nervous system and special sensesapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about Z45.321

Is Z45.321 billable?

Yes. Z45.321 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can Z45.321 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict Z45.321 as a principal diagnosis.

Is Z45.321 a CC or MCC?

No. Z45.321 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does Z45.321 group to?

Z45.321 is used in the MS-DRG v44.0 logic for MS-DRG 154 (Other Ear, Nose, Mouth and Throat Diagnoses with MCC), MS-DRG 155 (Other Ear, Nose, Mouth and Throat Diagnoses with CC) and MS-DRG 156 (Other Ear, Nose, Mouth and Throat Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for Z45.321?

The CMS General Equivalence Mappings map Z45.321 to ICD-9-CM V53.09.