After numerous delays, the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) was implemented in the United States on October 1, 2015 as the standard for diagnosis code reporting.

ICD-10-CM contains 21 chapters listing three to seven digit alphanumeric codes. Currently there are more than 79,000 ICD-10-CM diagnosis codes, which is about 65,000 more codes than currently exist in ICD-9-CM.

ICD-10-CM allows coding for increased specificity in the reporting of diseases and recently recognized conditions. Further, ICD–10–CM provides noteworthy improvements over ICD–9–CM in coding primary care encounters, external causes of injury, mental disorders, neoplasms, and preventive health. The ICD–10–CM code set reflects advances in medicine and medical technology, permits the capture of more socioeconomics details, ambulatory care condition information, problems related to lifestyle, and the results of screening tests.

ICD-10 implementation means that physicians need to ensure that their chart documentation will support the increased clinical specificity of the new code set. This will enable proper code selection and will result in fewer claim denials.

ICD-10 provides additional clarity that benefits obstetrics and gynecology coding. Some of the obstetrical coding enhancements include:

1. Elimination of episodes of care for obstetric codes
2. Changes in time frames:

  1. Abortion vs. Fetal death (20 weeks)
  2. Early vs. Late pregnancy (20 weeks)
  3. Code extensions to denote the specific fetus in multiple gestation pregnancies

One other notable enhancement is that ICD-10-CM allows the trimester of pregnancy to be designated. Here is an example of the difference:

649.53 Spotting complicating pregnancy, antepartum O26.851 Spotting complicating pregnancy, first trimester
  O26.852 Spotting complicating pregnancy, second trimester
  O26.853 Spotting complicating pregnancy, third trimester
  O26.859 Spotting complicating pregnancy, unspecified trimester

Note that the ICD-10-CM diagnostic codes for obstetrical conditions begin with the letter "O".

ICD-10-CM also provides the ability to report the specific gestational week of pregnancy with codes from category Z3A. Gestational week codes would be reported in addition to codes for complications of pregnancy.  Here is an example of the gestational week code structure:

Z3A.0 Weeks of gestation of pregnancy, unspecified or less than 10 weeks
Z3A.00 Weeks of gestation of pregnancy not specified
Z3A.01 Less than 8 weeks gestation of pregnancy
Z3A.08 8 weeks gestation of pregnancy
Z3A.09 9 weeks gestation of pregnancy

Annual updates to ICD-9 CM and ICD-10 would have made transition planning difficult, so, vendors, system maintainers, payers, and educators requested a code freeze. As a result, the last regular, annual updates to both ICD-9-CM and ICD-10-CM were made on Oct 1, 2011. Limited code updates in years 2012 - 2015 were permitted in order to capture new technology and new diseases:

October 1, 2011 – last regular updates to ICD-9-CM and ICD-10-CM/PCS occurred
October 1, 2015 – implementation date for ICD-10-CM/PCS.
October 1, 2016 – regular updates to ICD-10-CM/PCS will begin.


ACOG is offering multiple ICD-10-CM training opportunities. The 2016 Coding Workshop schedule has been posted! We expect registrations to be brisk.  If you are interested in attending a 2016 Coding Workshop don’t delay! Click here to register now.

In the meantime, ACOG’s coding resources provide tools and guidance needed to code claims faster and more accurately.


Donna Tyler
Manager, Coding Education

Keisha Sutton
Coding Specialist

American Congress of Obstetricians and Gynecologists
409 12th Street SW, Washington, DC  20024-2188 | Mailing Address: PO Box 70620, Washington, DC 20024-9998