ICD-10 and the ob/gyn


The transition to ICD-10 is looming. You'll be ready if you start planning now.

If you’re getting bored with implementing all the changes in health care wrought by the Affordable Care Act, federal electronic medical record (EMR) mandates, value-based purchasing penalties, increased Medicare audits, unannounced visits from the Joint Commission, and escalating scrutiny from your state’s department of health, you are in luck. In about a year, on October 1, 2014, the nation will switch from ICD-9 to ICD-10 codes. This transition will likely be expensive and will certainly be stressful for both you and your office staff.

My advice is to prepare now.

A brief history of the ICD classification system

In 1948 the newly formed World Health Organization (WHO) sought to establish a worldwide system to classify illnesses to promote better measurement of public health outcomes across countries. The resultant lists became the International Classification of Diseases (ICD). Its ninth iteration was released by the WHO in 1977 but it took the United States another 6 years to adopt a clinically modified version (ICD-9-CM), primarily to facilitate Medicare billing.1

We have been using various modifications of this system for the past 30 years. The ICD-9-CM codes consist of 3 volumes. The first 2 volumes deal with disease diagnoses and the third, unique to the United States, addresses inpatient procedures.

The federal government contends that the now-36-year-old classification system is simply too old, too unsophisticated, and too limited to justify continued use. Indeed, many classification categories have no additional “space” to permit cataloging of newly discovered disease variants and new procedures.

Moreover, the government also argues that ICD-9 lacks the level of detail needed to facilitate accurate billing, track public health outcomes, and identify emerging pandemics, as well as support health systems’ quality improvement and resource utilization efforts.

Ironically, the United States is introducing the ICD-10 classification system nearly 20 years after it was implemented in most other WHO countries, and at a time when the rest of the world is gearing up for ICD-11. Then again, we still measure distance in inches and miles in this country.

How will ICD-10 work and how does it differ from ICD-9?

The ICD-10 system has 2 different components. The first, ICD-10-CM, is based upon the 1990 WHO ICD-10 as modified by the Centers for Disease Control and Prevention and the National Center for Health Statistics. The ICD-10-CM system focuses on disease classification and increases by nearly 5-fold the number of diagnostic codes in ICD-9-CM, from about 14,000 to 68,000.2

The second component is the ICD-10-PCS (procedure classification system), which increases the number of procedure codes nearly 20-fold compared with the old ICD-9-CM (volume 3) procedure set, from around 4,000 to 87,000.3 The ICD-10-PCS system was developed by the Centers for Medicare and Medicaid Services (CMS) aided by 3M Health Information Management, and is for use only in United States inpatient settings.3 It should not be confused with, and is not meant to replace, the American Medical Association’s CPT (Current Procedural Terminology) codes, which are designed to characterize services rendered by providers in both outpatient and inpatient settings (eg, CPT 59400 – antepartum care, delivery and postpartum care).4

As noted above, the federal government contends that ICD-10 will improve everything from billing access to our ability to detect impending pandemics. Indeed, it is true that ICD-10 codes add a great deal more relevant clinical information. For example, the ICD-9 system does not address laterality (ie, it doesn’t distinguish among left, right, and bilateral lesions) nor the episode of care (ie, whether a presentation is initial or subsequent).

The ICD-9 system also lacks any real clinical specificity. For example, where there was one ICD-9 code for a closed fracture of the femur (821.01) there now will be at least 24 codes dealing with such fractures (eg, ICD-10 code S72325G is for “Nondisplaced transverse fractures of the shaft of the left femur, subsequent encounter for closed fracture with delayed healing”).

The ICD-10 codes are structurally more complex than the ICD-9 codes. Each ICD-10 code can have 3 to 7 alphanumeric characters instead of ICD-9’s 3 or 4. The ICD-10-CM codes have 3 to 7 alphanumeric characters, with the first character always being a letter, the second always a number, and the remaining 5 characters either letters or numbers. All letters are used except U. A decimal point is placed after the first 3 characters. Laterality can be noted in the 5th or 6th digit (1 = right; 2 = left; and 3 = bilateral).2 Certain CM code categories, including certain obstetrical ones, always require a 7th character that reflects either the encounter type (usually used with injuries, e.g., A = initial; D = subsequent or S = sequelae), or the identity of the fetus in a multi-fetus pregnancy.


If there are fewer than 6 other characters used for a CM code in which a 7th character is required, the dummy placeholder “x” must be used to present all 7 values (eg, O69.0xx3 labor and delivery complicated by prolapse of cord, fetus # 3). The ICD-10-CM codes are contained in 21 chapters, including Chapter 2, Neoplasms (C00-D48); Chapter 14, Diseases of the genitourinary system (N00-N99), which includes N70-N77 - Inflammatory diseases of female pelvic organs and N80-N98 -Noninflammatory diseases of female pelvic organs; and Chapter 15, Pregnancy, childbirth and the puerperium (O00-O99).

The ICD-10-PCS codes use all 7 characters without a decimal point. Each character can be either a number or a letter, creating 34 possible values (10 numbers from 0 to 9 plus 24 letters). Thus, there is plenty of “room to grow” to accommodate new procedures. The letters O and I are not used to avoid confusion with the numbers 0 and 1. All the ICD-10-PCS codes can be derived from the 16 separate sections delineated by the first character in the 7-digit sequence (eg, 0 for medical and surgical procedures, including gynecological surgery, 1 for obstetrical procedures, B for imaging, G for mental health, etc.). That is, the first digit defines the broad procedure category in which a given code can be located.

Changes relevant to ob/gyn

There are twice as many obstetrical codes in ICD-10-CM (2,155) as in ICD-9 (1,104).5 These new codes add specificity to the characterization of obstetrical conditions. As noted, the ICD-10-CM obstetric codes are listed in Chapter 15. These codes have sequencing priority over those from other chapters and start with the letter “O,” not the number zero.

Unlike the ICD-9 codes, ICD-10-CM obstetrical codes are not divided by antepartum, delivery, and postpartum status, but most new codes indicate the trimester of pregnancy in their final character.6 An additional code from category Z3A should be used to define specific weeks of gestation (eg, Z3A.42 would indicate 42 weeks’ gestation). The Z codes connote reasons for encounters in the ICD-10 system.

There are now more codes to describe the nature of medical complications in pregnancy. For example, when diabetes complicates pregnancy it can be further classified as pre-existing (type 1 or 2) and by the trimester in which the encounter occurred (e.g., O24.011 defines “Pre-existing diabetes mellitus, type 1, in pregnancy, first trimester”). Alternatively, gestational diabetes can be described along with its treatment (O24.011 defines “Gestational diabetes mellitus in pregnancy, diet controlled”).

Conversely, routine office visits during uncomplicated pregnancies require a code from category Z34 (“Encounter for supervision of normal pregnancy”) as the first‐listed diagnosis, but no codes from Chapter 15.7 When a patient has had a full-term uncomplicated delivery of a healthy singleton fetus following an uncomplicated pregnancy and postpartum course, code O80 is used and no others from chapter 15. This code should be accompanied by Z37.0 (Single live birth) as the only outcome-of-delivery code.

The ICD-10-CM codes for elective abortion are contained in Chapter 21 (Factors Influencing Health Status and Contact with Health Services). As noted, Chapter 14 (N00-N99) itemizes diseases of the genitourinary system, which include diagnoses related to the female reproductive and urinary tracts.

As noted above, in ICD-10-PCS, obstetrical procedure codes are designated by the number 1 in the first character of the code, as opposed to medical and surgical procedures, which are designated by the number 0 (zero). For obstetrical procedures, the second character is 0 (zero), connoting pregnancy, and procedures are further characterized by the remaining 5 digits. Conversely, gynecological surgery is listed under the medical and surgical first character 0 (zero), and then by second character U indicating the female reproductive body system (ie, 0U) and further defined by the other 5 digits (note that while U is not used in ICD-10-CM codes, it is used for PCS codes).

Preparing for ICD-10

Implementation of ICD-10 will require extensive preparation by physicians and their office staff. Billing software will need to be updated, forms changed, and staff trained in the new codes. ICD-10 implementation will also require that coders have a greater knowledge of anatomy, physiology, and medical terminology.2

For physicians, implementation will require far more elaborate documentation, because a much higher level of detail is needed to support the more specific ICD-10 codes. Courses and checklists can help. For practices with compatible EMRs, new computer-assisted coding (CAC) programs may also be worth the investment. These programs abstract data using natural language processing and generate suggested ICD-10 codes based on the text words entered.

An organized approach to implementation is necessary, starting with an impact assessment and a careful inventory of all the office practice changes required to permit the ICD-10 roll-out.2 Planning should include a timeline of requisite steps. Coordination with payors and testing of systems will also be necessary. However, even with these steps, there is evidence that use of ICD-10 is associated with increased coding time and delays in accounts receivable.2 Implementation also will not be cheap. One estimate of the cost for a 3-person practice is around $83,000, rising to $285,000 for a larger 9- to 10-physician practice.8 These figures are likely to be lower for ob/gyn offices because of the smaller number of new codes used on a regular basis.

Take-home message

Like it or not, ICD-10 is coming. It holds the promise of improved public health, hospital quality assurance, patient safety, and resource utilization, and may reduce CMS fraud and abuse. On the other hand, it will certainly increase practice costs and the workload of all physicians and their office staff. However, use of CAC and more advanced EMRs may mitigate some of the workload and expense. Finally, because the United States is the last developed nation on the planet not to embrace the ICD-10 system, its time has certainly come.


1. Mitchell M. The history of ICD 9 coding. http://www.ehow.com/about_5389427_history-icd-coding.html. Accessed August 20, 2013.

2. AAPC. ICD-10: The history, the impact and the keys to success. http://aapcmarketing.s3.amazonaws.com/documents/AAPC_ICD-10_white_paper.pdf. Accessed August 20, 2013.

3. ICD-10 coding: ICD-10-CM vs. ICD-10-PCS. http://www.icd10codesearch.com/coding.php. Accessed August 20, 2013.

4. HealthCare Information Management, Inc. What is the difference between ICD-10-CM and ICD-10-PCS? http://www.hcim.com/2010/04/what-is-the-difference-between-icd-10-cm-and-icd-10-pcs/. Accessed August 20, 2013.

5. Carmichael A. Exploring ICD-10-CM’s Chapter 15: pregnancy, childbirth & the puerperium. http://www.icd10monitor.com/index.php?option=com_content&id=415:exploring-icd-10-cms-chapter-15-pregnancy-childbirth-a-the-puerperium&Itemid=106. Accessed August 20, 2013.

6. AAPC. Ob/gyn quick reference for ICD-10-CM. http://cloud.aapc.com/documents/OB-GYN-Quick-Reference_ICD-10-CM.pdf. Accessed August 20, 2013.

7. ICD‐10 coding fact sheet: obstetrics and gynecology. http://www.gkcmma.com/sites/www.gkcmma.com/files/resources/ICD-10_OBGYN_Fact_Sheet.pdf. Accessed August 20, 2013.

8. Meyer H. Coding complexity: US health care gets ready for the coming of ICD-10. Health Aff. 2011;30(5):968-974.


Related Videos
Unveiling gender disparities in medicine | Image Credit:  findcare.ahn.org.
John Stanley, MD
Related Content
© 2024 MJH Life Sciences

All rights reserved.