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  6. 2025 ICD-10-CM Code Z3A.16

2025 ICD-10-CM Diagnosis Code Z3A.16

16 weeks gestation of pregnancy

ICD-10-CM Code:
Z3A.16
ICD-10 Code for:
16 weeks gestation of pregnancy
Is Billable?
Yes - Valid for Submission
Code Navigator:

Z3A.16 is a billable diagnosis code used to specify a medical diagnosis of 16 weeks gestation of pregnancy. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

The code Z3A.16 is applicable to female patients aged 12 through 55 years inclusive. It is clinically and virtually impossible to use this code on a non-female patient outside the stated age range.

Code Classification

  • Factors influencing health status and contact with health services
    Z00–Z99
    • Persons encountering health services in circumstances related to reproduction
      Z30-Z39
      • Weeks of gestation
        Z3A

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Gestation period, 16 weeks

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Gestational weeks

CCSR Code: PRG002

Inpatient Default: X - Not applicable.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Code Edits

The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.

Maternity diagnoses

The Medicare Code Editor detects inconsistencies in maternity cases by checking a patient's age and any diagnosis on the patient's record. The maternity code edits apply to patients age ange is 9–64 years inclusive (e.g., diabetes in pregnancy, antepartum pulmonary complication).

View Edit

Unacceptable principal diagnosis

There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

View Edit

Present on Admission (POA)

Z3A.16 is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.

CMS POA Indicator Options and Definitions

POA Indicator: Y

Reason: Diagnosis was present at time of inpatient admission.

CMS Pays CC/MCC DRG? YES

POA Indicator: N

Reason: Diagnosis was not present at time of inpatient admission.

CMS Pays CC/MCC DRG? NO

POA Indicator: U

Reason: Documentation insufficient to determine if the condition was present at the time of inpatient admission.

CMS Pays CC/MCC DRG? NO

POA Indicator: W

Reason: Clinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.

CMS Pays CC/MCC DRG? YES

POA Indicator: 1

Reason: Unreported/Not used - Exempt from POA reporting.

CMS Pays CC/MCC DRG? NO

Convert Z3A.16 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

ICD-9-CM:

Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.

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Patient Education


Pregnancy

You're going to have a baby! It's an exciting time, but it can also feel a bit overwhelming. You may have a lot of questions, including what you can do to give your baby a healthy start. To keep you and your baby healthy during pregnancy, it is important to:

  • Have regular visits with your health care provider. These prenatal care visits help make sure that you and your baby are healthy. And if there are any health problems, your provider can find them early. Getting treatment right away can cure many problems and prevent others.
  • Eat healthy and drink plenty of water. Good nutrition during pregnancy includes eating a variety of:
    • Fruits
    • Vegetables
    • Whole grains
    • Lean meats or other protein sources
    • Low-fat dairy products
  • Take prenatal vitamins. During pregnancy, you need higher amounts of certain vitamins and minerals, such as folic acid and iron.
  • Be careful with medicines. Always check with your provider before you start or stop any medicine. This includes over-the-counter medicines and dietary or herbal supplements.
  • Stay active. Physical activity can help you stay strong, feel and sleep better, and prepare your body for birth. Check with your provider about which types of activities are right for you.
  • Avoid substances that could hurt your baby, including alcohol, drugs, and tobacco.

Your body will keep changing as your baby grows. It can be hard to know whether a new symptom is normal or could be a sign of a problem. Check with your provider if something is bothering or worrying you.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.