American Osteopathic Association

Advancing the distinctive philosophy and practice of osteopathic medicine

ICD-10: Frequently Asked Questions

1. Why is there a change from ICD-9 to ICD-10?

The reason for this change is that the ICD-9 code set is outdated and running out of space for new codes. The terminology used is from the 1980s, and does not accurately reflect the changes in practice, the discovery of new diseases and treatments, and some of the recommended standards of treatment which have become widespread. It is no longer capable of capturing important information for public health tracking, research, and improvement; nor can it support the recent needs for biosurveillance. Quality measurement–a key component of changing health care reimbursement models–was stymied by the lack of specificity in the ICD-9 code set.

As for the change in the codes, they will now contain quite specific information.

2. When do I have to use ICD-10 codes?

After several delays, ICD-10 codes must be used to indicate the diagnoses on all transactions (claims, pre-authorizations, etc.) for services delivered on and after Oct. 1, 2015. 

3.  Who has to use the ICD-10 codes?

All health plans, clearinghouses, and providers who do electronic transactions must use ICD-10 codes to indicate diagnoses. Health plans are expected to require ICD-10 codes on paper transactions also. Note that workers' compensation plans, auto insurance, and property and casualty plans are not subject to this federal requirement. Their requirements are set by each state. Some states are already requiring ICD-10 codes for these plans, while others are not.

4. If I don’t see Medicare patients, will I have to use ICD-10 codes?

Everyone covered by HIPAA must use ICD-10 starting Oct. 1, 2015.

5. Will ICD-10 codes replace CPT procedure codes?

No. The switch to ICD-10 does not affect CPT coding for outpatient procedures. Like ICD-9 –CM, ICD-10 are diagnosis codes.

6. What is the biggest change that ICD-10 will cause for providers?

Because ICD-10 codes are more specific than ICD-9 codes, to accurately code a diagnosis more specific documentation will be required. Many unspecified codes have been eliminated. Therefore, documentation processes currently used by providers will have to be revised to collect the appropriate information for ICD-10 diagnosis coding.

7. Do I have to learn the whole code set?

No. Just as you do today, you only need to understand that codes that are relevant to your practice. The ICD-10 code set is well organized so that your relevant codes are easy to find. 

8. Where can I find the ICD-10 codes?

The ICD-10-CM, ICD-10-PCS code sets and the ICD-10-CM official guidelines are available free of charge on the CMS website.

9. Where are the somatic dysfunction codes located in ICD-10?

The codes for somatic dysfunction  are located in Chapter 13; Diseases of the Musculoskeletal System and Connective Tissue (M00 – M99).

10.  Why can’t I just buy a translator to go from ICD-9 to ICD-10?

There is no exact translation from every ICD-9 code to the best ICD-10 in every situation.  First, the ICD-10 codes are more specific, so additional information is necessary to get to the right code (e.g. specific bone which is broken, severity of disease). Second, there have been changes in several sections of the code set so that a direct translation is not possible (e.g. obstetric codes now require the trimester, which was not indicated in the ICD-9 code).

11. Is there ICD-10 training available?

The AOA has resources available at The CMS website has an extensive set of information and HIMSS has an ICD-10 Playbook containing additional resources.

12. What type of training will providers and staff need for the ICD-10 transition?

AHIMA recommends training should begin no more than six months before the compliance deadline. Every area of your practice will be affected by ICD-10 and therefore the extent of training required will depend on the staff position. Training varies from someone needing to know the basics (two to four hours) to coders (30 to 50 hours).

ICD-10 resources and training materials are available through the AOA, CMS, professional associations and societies, and software/system vendors.

13.  How long will ICD-10 implementation take for me?

While each practice differs, the general guidance is that a well-planned and orderly implementation would take about 18 months. As we are closer to the compliance date than that, the process must be shortened. Practices should expect to spend nine to 12 months on assessment, remediation, training, and testing.

14. Can’t my practice management and EHR vendor take care of ICD-10 for me?

While they will contribute, much of the ICD-10 implementation will be the responsibility of the practice.  You are responsible for the collection of information and documentation used to choose the correct ICD-10 diagnosis code(s) for each patient encounter. Your vendor products will allow you to enter the codes, and may give some guidance based on the documentation collected. 

15. What should I be discussing with my vendor regarding ICD-10?

First, you need to understand what the changes are that the vendor is proposing for ICD-10 to determine if they will meet your needs, and then what changes you may need to make to accommodate the vendor changes.  Will the new products support both ICD-9 and 10?  How? Will you be able to directly enter an ICD-10 code (preferred), or will the product do some sort of mapping from ICD-9 to 10? Secondly, you will need to know the vendor schedule for product remediation, vendor testing, customer beta testing, and then installation. It is imperative that the vendor install new products in time for you to understand, test, and then fully implement the product. And thirdly, determine what sort of support the vendor will provide both before and after the Oct. 1 compliance date. A template letter on ICD-10 readiness to send to vendors may be helpful and is available to AOA members (login required).

16. What types of things will I need to include in my documentation?

You will need to include details such as laterality, severity, stage and specific type and order.  For specific conditions, requirements will vary; some examples for common conditions in family medicine include:

  • Asthma: intermittent, mild persistent, moderate persistent, severe persistent

  • Fractures: Gustilo classification, type of fracture

  • Seizures: General or focal, what type, intractability

  • Pregnancy: Which trimester

  • Poisoning or toxic effect: Which substance

  • Ulcers: Which stage

17.  What changes will ICD-10 cause at health plans?

Just as at providers, many processes at health plans use diagnosis codes. You can expect changes in medical review requirements, requests for additional information, changing quality measures, changes in coverage determinations, and changes in payments. While the CPT/HCPCS codes will still be used as the main determinant of physician payment, the more specific ICD-10 diagnosis codes will be used more and more to impact the payments.

18. If I am ready to begin using ICD-10 codes will CMS process my claims?

No. CMS and other payers will not be able to process claims using ICD-10 until Oct. 1, 2015. However, organizations will need to work with internal team and business trading partners to test their software systems from beginning to end prior to the Oct. 1, 2015 date.

19. If I want to start testing who should I contact?

If you would like to start testing with CMS you can contact your local Medicare Administrative Contractor (MAC) to arrange acknowledgement. To test with your commercial carriers contact your provider representative.

20. How will I report ICD-10 codes on claims when the dates of service span from prior to Oct. 1, 2015 to on or after that date?

Many payers are requiring claims with dates of service that span the Oct. 1, 2015 implementation date to be split so that the services prior to Oct. 1, 2015 are billed separately and utilize ICD-9 codes; services on and after Oct. 1, 2015 are billed separately and utilize ICD-10 codes.

Check specific payer guidelines for processing claims for services that span the Oct. 1, 2015 ICD-10 transition date.

21. How long after the Oct. 1, 2015, ICD-10 compliance date must I continue to report and/or process ICD-9 codes?

Each payer determines their late filing requirements for standard transactions and ICD-10 does not require a change to these requirements. These deadline requirements vary among plans. Contact your payer for the current information regarding late filing for claims. 

22. What should providers do now to prepare for the transition to ICD-10?

View AOA ICD-10 timeline for suggested steps you can be working on now to make the Oct. 1, 2015 transition to ICD-10 run smoothly for your practice.


Are there ICD-10 questions that we haven’t answered? If so please send your ICD-10 question to and ICD-10 expert Stanley Nachimson will provide the answer.

About the author: Stanley Nachimson is the author of the authoritative paper on the cost of ICD-10 for physician practices and is co-chairing the HIMSS ICD-10 Task Force. He is principle of Nachimson Advisors Nachimson Advisors, a health IT consulting firm.