Diagnostic Coding

CHAPTER OUTLINE

DIAGNOSTIC CODING LOCATING THE APPROPRIATE THE FUTURE OF DIAGNOSTIC Inpatient Versus Outpatient Coding CODE CODING: INTERNATIONAL Using the ICD-9-CM Conventions CLASSIFICATION OF DISEASES, ICD-9-CM: THE CODE BOOK Main Term TENTH REVISION Volume 1: Tabular List of Diseases Fourth and Fifth Digits Volume 2: Alphabetic Index to Primary Codes Diseases When More Than One Code Is Volume 3: Inpatient Coding Used Coding Suspected Conditions Documentation Requirements ROLE DELINEATION COMPONENTS

GENERAL: Legal Concepts • Obtain reimbursement through accurate claims • Perform within legal and ethical boundaries submission

ADMINISTRATIVE: Administrative Procedures ADMINISTRATIVE: Practice Finances • Perform basic administrative medical assisting • Perform procedural and diagnostic coding functions

CHAPTER COMPETENCIES

LEARNING OBJECTIVES Upon successfully completing this chapter, you will be able to: 1. Spell and define the key terms 4. Describe the relationship between coding and 2. Name and describe the coding system used to reimbursement describe diseases, injuries, and other reasons for 5. Explain the format of the ICD-9-CM encounters with a medical provider 6. List the steps in identifying a proper code 3. Give four examples of ways diagnostic coding is 7. Name common errors in outpatient diagnostic used coding

KEY TERMS advance beneficiary notice etiology late effects primary diagnosis audits inpatient main terms service conventions International Classification of medical necessity specificity cross-reference Diseases, Ninth Revision, outpatient V-codes E-codes Clinical Modification eponym

279 280 Section II ■ The Administrative Assistant

CODING, AT ITS SIMPLEST, is the assignment of a number based on the International Classification of Diseases, Ninth Re- to a verbal statement or description. Medical coding is any- vision (ICD-9), developed by the World Health Organization thing but simple. The International Classification of Dis- (WHO). The CM, which stands for clinical modification, eases, Ninth Revision, Clinical Modification is a system for addresses the intent of these codes to describe the clinical transforming verbal descriptions of disease, injuries, condi- picture of the patient. These codes are much more precise tions, and procedures into numeric codes. It is essential that than those needed for statistical grouping and trend analysis the physician and medical assistant work together to achieve found in the ICD-9 and used in hospital coding. accurate documentation, code assignment, and reporting of The ICD-9-CM, which is now mandated by Health Insur- diagnoses and procedures. Use of standardized codes makes ance Portability and Accountability Act of 1996 (HIPAA), is it easier for third-party payers to understand the reason for the most current and comprehensive statistical classification the patient’s encounter with the health care provider and in- of its kind. Containing more than 10,000 diagnostic codes creases the likelihood of timely processing of claims and and 1,000 procedure codes, it consists of three volumes: prompt payment when appropriate. Coding is a way to standardize medical information for • Volume 1: Tabular List of Diseases purposes such as collecting health care statistics, performing • Volume 2: Alphabetic Index of Diseases a medical care review, and indexing medical records. It is also • Volume 3: Tabular List and Alphabetic Index of Pro- used for health insurance claims processing (see Chapter 16). cedures Because coding is the basis for reimbursement, it is imperative The ICD-9-CM code books are available from several that you code patient visits accurately and precisely. Incorrect, publishers, and although the presentation of the material may insufficient, or incomplete coding on claims forms can lead to be different, the content must be the same. Depending on the nonpayment for the physician as well as incorrect information publisher, these three volumes may be included within one in the insurance companies databases, which may effect the book. In the physician’s office, only Volumes 1 and 2 are patient’s insurability. For example, if a patient complaining of used. Volume 3 is used by hospitals. chest pain is coded as having “acute myocardial infarction” in- The diagnostic classification systems in Volumes 1 and 2 stead of “chest pain rule out myocardial infarction,” that pa- are maintained by a federal government agency, the National tient may be incorrectly labeled as having heart disease. The Center for Health Statistics (NCHS); the procedure classifi- Current Procedural Terminology (CPT) codes, used to report cation (Volume 3) is maintained by the Centers for Medicare services and procedures performed by health care providers, determine the amount paid (see Chapter 18), but the code as- & Medicaid Services (CMS), the federal agency that regu- signed to the diagnosis or reason for the service or procedure lates health care financing. All three volumes are updated proves the medical necessity for the services or procedures so regularly, with codes being added, revised, and sometimes that claims are paid. The third-party payer needs to know why deleted. Changes in the ICD-9-CM are published by NCHS the service was performed to assess medical necessity. Med- and CMS with the approval of WHO. Both the American ical necessity means the procedure or service would have been Health Information Management Association (AHIMA) and performed by any reasonable physician under the same or sim- the American Hospital Association (AHA) advise and assist ilar circumstances. The ICD-9 diagnostic codes convey this in- in keeping the classification system current. formation. Is a chest radiograph medically necessary for a patient who has gout? No, but it may be necessary for a patient Checkpoint Questions with acute bronchitis. The diagnosis justifies the procedure. Since Medicare considers certain procedures medically 2. What are the three volumes of the ICD-9-CM necessary only at certain intervals, having the patient sign an system? advance beneficiary notice (ABN) will ensure payment of 3. What organization must approve any changes in treatments and procedures that will likely be denied by the disease classification system? Medicare. An example is a Pap smear for a low-risk woman, which will be paid for once every 2 years. If the physician Inpatient Versus Outpatient Coding considers it not to be medically necessary, but the patient wants a Pap test, the patient will be responsible for payment There is a big difference between coding medical claims in a and must sign an ABN. hospital or other inpatient facility and coding for the physician in an outpatient medical practice. The systems and references used to assign codes to third-party claims is only one Checkpoint Question difference in the coding requirements and practices of the 1. What is meant by medical necessity? physician and the inpatient medical facility. Volumes 1 and 2 of the ICD-9 CM are used to report the diagnostic code that DIAGNOSTIC CODING justifies physician services whether those services are provided in the office or in the hospital. Hospital coders use International Classification of Diseases, Ninth Revision, Clinical Volume 3 to report inpatient procedures, services, and sup- Modification (ICD-9-CM) is a statistical classification system plies, as well as the reasons for the services. Chapter 17 ■ Diagnostic Coding 281

The UB-92 (uniform bill) is used by institutions to report addition to using a code book, you will need reference mate- inpatient admissions and outpatient and emergency depart- rials such as a medical dictionary and/or medical dictionary ment services and procedures. These charges are for nursing software. services, building maintenance, and all costs associated with To ensure accurate coding, update your ICD-9-CM coding running the institution. These charges do not include physi- books and software as needed. (Updates and addenda can be cian services. The CMS-1500 (universal claim form) is used purchased from the publisher of your coding book.) You to report physician services, whether the physician sees the must update codes on superbills (preprinted bills listing a va- patient in the office, emergency department, hospital, or riety of procedures) or any other forms you use. Experts nursing home, because even though the physician may have have estimated that millions of dollars in reimbursement been in the hospital, it is his service for which we are billing have been lost because an incorrect code was taken from a in the medical office. standardized form that had not been updated. New codes are The term outpatient is used to describe patients treated in published each October, and most third-party payers require the following places: their use after January 1. • Health care provider’s office • Hospital clinic Checkpoint Question • Emergency department 5. How often is the ICD-9-CM updated? • Hospital same-day surgery unit or ambulatory surgical center that releases the patient within 23 hours • Observation status in a hospital (the patient is admitted Volume 1: Tabular List of Diseases for a short time for observation only, and the physician Volume 1 contains the classification of diseases (conditions) bills for his or her service during the stay) and injuries by code numbers. Figure 17-1 shows the table of The term inpatient refers to a patient who is admitted to contents from this volume. These 17 chapters cover group- the hospital for treatment with the expectation that the pa- ings of diseases and injuries by etiology or cause (e.g., in- tient will remain in the hospital for 24 hours or more. fectious diseases) and by anatomic system (e.g., digestive, Hospital coders code only services provided by the hospi- respiratory). Each chapter has a heading or title (e.g., 16, tal and hospital employees. Coders who are employed by the Symptoms, Signs, and Ill-defined Conditions (780–799). physician practice are concerned with the services provided Following the title in parentheses is the range of three-digit by the physician no matter where the services are provided. categories included in that chapter. In each chapter you will For example, the hospital room, meals, and laboratory test- find subtitles in large type followed by a range of three-digit ing that a patient receives are billed and coded by the hospi- categories in parentheses (e.g., 16, Symptoms (780–789). tal billing department. The daily visits the physician makes These sections describe general disease. Three-digit codes to the patient are billed and coded by the physician’s office. followed by a title, the category codes, describe specific dis- Since the focus of this textbook is medical assisting, we eases (e.g., 780, general symptoms). The fourth digit further concentrate on outpatient coding. breaks down the category (e.g., 780.0, alteration of con- sciousness), and the fifth digit is the highest level of definition (e.g., 780.01, coma). Figure 17-2 is a sample page from Checkpoint Question the tabular list showing each level of classification. 4. Define the terms inpatient and outpatient. Volume 1 is always used to code a diagnosis to its highest definition. This volume tells you how many digits are re- ICD-9-CM: THE CODE BOOK quired to code a diagnosis correctly and to a level that most third-party payers will accept. Volume 1 also includes five Coding books are available from several publishers, such as appendices, outlined in Box 17-1. Ingenix and Medicode. The AMA (American Medical Asso- ciation) Press also publishes coding books and training Supplementary Classifications materials. The classification system is also available as part of a medical software package; one of these packages is Supplementary classifications in Volume 1 include V- and CodeManager from the AMA. Although each publisher of- E-codes. fers special features and helpful aids, the format remains the same. Some coders become comfortable with certain special V-Codes. V-codes, which range from V01 to V82, provide features (i.e., AMA publications are spiral bound) and, since a means of indexing the reason for hospital or physician of- the content is the same, can choose among the various pub- fice care for other than current or genuine illness, such as a lications based on organization, illustrations, tabs, bullets, history of illness, immunizations, or live-born infants ac- and color coding. cording to type of birth. An example of a V-code is V10.04, To become an expert medical coder, you need general used for a person with a personal history of a malignant neo- knowledge of human anatomy and medical terminology. In plasm of the stomach. Because of this history, it would be 282 Section II ■ The Administrative Assistant

F IGURE 17–1. Table of contents from ICD-9-CM, Volume 1.

important for this patient to have regular checkups. You E-Codes. E-codes, which range from E800 to E999, are would not want to code the visit 230.2, neoplasm of the used to classify external causes of injuries and poisoning. stomach, because that would imply the patient has the ma- Specificity is limited to the fourth digit level. E-codes are lignant neoplasm at this visit. The ICD-9-CM offers a vari- used in conjunction with codes in Chapters 1 to 17. They help ety of codes for HIV testing. The patient who is simply afraid to provide information of interest to industrial medicine, in- carries one V-code, while the patient who has known expo- surance underwriters, national safety programs, public health sure carries another. V-codes may be used alone if no disease agencies, and others concerned with causes of injuries (e.g., diagnosis is appropriate or as the second or third code to help auto accidents, accidents caused by heavy industrial machin- better explain the reason for the visit. ery). These codes do not affect reimbursement. Chapter 17 ■ Diagnostic Coding 283

F IGURE 17–2. Sample page from ICD-9-CM, Volume 1, showing categories, subheadings, and so on. 284 Section II ■ The Administrative Assistant

Volume 2. In Volume 1 they are all listed under code 110.0. Box 17-1 The index is arranged by condition. Always check all inden- tations in the index under the condition to ensure that you ICD-9-CM APPENDICES have the one most appropriate to the diagnosis you intend The following five appendices are found in Volume I to code. • Appendix A: Morphology of Neoplasms The alphabetic index is organized into three sections: This appendix is used in conjunction with Chap- • Section 1, Alphabetic Index to Diseases and Injuries, is ter 2 in ICD-9-CM when coding neoplasms. It lists organized by main terms printed in boldface type. the five-digit alphanumeric codes used to identify Section 1 is used for reporting the reason for patient the morphology of a neoplasm. For example, in the encounters for most insurance claims. Following the morphology code M8070/3, the 8070 indicates the main term is a code number, which refers you to the morphology is squamous cell carcinoma. The /3 in- tabular listing (Volume 1). You must not accept this dicates that it is the primary site. number as the correct code without a cross-reference • Appendix B: Glossary of Mental Disorders or check of the tabular list. Never code directly from Alphabetic list of mental disorders, including de- the alphabetic index. This could result in an incom- tailed descriptions of each disease. plete or incorrect coding assignment. For example, if • Appendix C: Classification of Drugs by American you have a patient with fluid overload and you look Hospital Formulary Service (AHFS) List Number under fluid, it may seem logical to code the first code and the ICD-9-CM Equivalents under fluid, which is abdomen, 789.5, but your patient This appendix lists the AHFS list number (e.g., is generally retaining fluid. If you use the alphabetic 24:04 for cardiac drugs) and the ICD9-CM code index only, you do not know that the correct code is number for each one (e.g., 24.04 cardiac drugs 276.6, fluid overload, which excludes ascites, 789.5, would be equivalent to category 972.9, the ICD9- and localized edema, 782.3. Box 17-2 lists several ex- CM category “other and unspecified agents prima- ceptions to the main term rule. rily affecting the cardiovascular system”). • Section 2, Table of Drugs and Chemicals, includes an • Appendix D: Classification of Industrial Accidents extensive listing of drugs, chemical substances, and by Agency toxic agents. It also shows E-codes and American Hos- This includes codes that can be used as a supple- pital Formulary Service (AHFS) list numbers, which ment to describe types of equipment or materials are in the table under the main term drug. that may be responsible for an industrial accident or • Section 3, Alphabetic Index to External Cases of In- illness. juries and Poisonings, leads you to codes that describe • Appendix E: List of Three-Digit Categories circumstances of injuries, accidents, and violence. This is a list of all three-digit categories in ICD- These codes are not used for medical diagnoses. Main 9-CM. entries in this section usually are a type of accident or Appendices A through D are not recognized by most violence (e.g., assault, fall, collision). These codes can government programs, such as Medicare and Medic- supplement the diagnostic code, but they should never aid. As previously mentioned, ICD-9-CM has other be used alone or as principal diagnosis codes. E-codes uses, however, and you may find that you need the appendices to track such things as disorders treated.

Box 17-2 Volume 2, Section 3, has a separate index to access E- codes, the Alphabetic Index to External Causes of Injury and EXCEPTIONS TO THE Poisoning. MAIN TERM RULE Keep in mind the following exceptions to this rule: Checkpoint Question 1. Obstetric conditions may be found under the main terms delivery, pregnancy, and puerperal. 6. List four reasons for using E-codes. 2. Complications of medical or surgical procedures can be found under complication. Volume 2: Alphabetic Index 3. Late effects are found under late effect. to Diseases 4. V-codes are found under main entries such as admissions, examination, history of observation, Volume 2, the alphabetic index to diseases, contains many problem (with), status, vaccination, encounter diagnostic terms that do not appear in Volume 1. For exam- for, and follow-up. ple, itch, barbers, beard, and scalp are all listed under Itch in Chapter 17 ■ Diagnostic Coding 285

¿Qué son todo estos números? What are all these numbers? Is that my bill? No, estos números se utilizan para su seguro. No, these numbers are used for your insurance. Estos se llaman los números de codificación. These are called coding numbers.

Box 17-3 are frequently used with these codes. For example, a person who fractured a tibia in a fall off a sidewalk CMS DIAGNOSTIC curb would be given a code from chapter 17, Volume 1, in the ICD-9-CM for the injury (e.g., fracture of CODING GUIDELINES tibia, closed, is 823.80), and an additional code, CMS defines specific guidelines that provide the basic E880.0, indicates that the accident was a fall off a side- knowledge necessary to apply the correct ICD-9 codes. walk curb. Although these guidelines were developed for use in submitting government claims, most insurance companies have also adopted them. Many variations exist Checkpoint Question among the private insurance companies; therefore, care 7. What are V-codes used for? must be taken in recognizing the different requirements for each third-party payer. Most coders operate on the Volume 3: Inpatient Coding assumption that the government regulations are the strictest, and following those guidelines will satisfy Volume 3, the Tabular List and Alphabetic Index of Proce- most third-party payers. dures, is used in inpatient facilities and is based on anatomy, 1. Identify each service and procedure, or supply not surgical specialty. There are no alphabetic characters in with an ICD-9 code from 001.0 through V82.9 to these procedure codes. The codes are two-digit categories describe the diagnosis, symptom, complaint, con- with a maximum of two decimal digits where necessary. dition, or problem. Most refer to surgical procedures, and the rest cover miscel- 2. Identify services or visits for circumstances other laneous diagnostic and therapeutic procedures. An example than disease or injury, such as follow-up care af- of a procedure code is 31.61, larynx laceration suture. Vol- ter chemotherapy, with V-codes provided for this ume 3 is used for inpatient coding only. purpose. 3. Code the reason for the visit first and code any LOCATING THE coexisting conditions that affect the treatment of APPROPRIATE CODE the patient for that visit or procedure as supplementary information. Do not code a diagnosis Box 17-3 outlines CMS guidelines for diagnostic coding. that is no longer applicable. These are explained next. 4. Code to the highest degree of specificity. Carry the numeric code to the fourth or fifth digit when Using the ICD-9-CM Conventions necessary. 5. Code a chronic diagnosis as often as it is applica- Figure 17-3 lists the conventions used in the ICD-9-CM in- ble to the patient’s treatment. dexes. Conventions are rules that apply to the assignment of 6. When only ancillary services are provided, list the ICD-9 codes. They are found throughout both the Index the appropriate V-code first and the problem sec- to Diseases and the Tabular List and include general notes us- ond. For example, if a patient is receiving only ing specific terms, cross-references, abbreviations, punctua- physical therapy, list the V-code first, followed tion marks, symbols, typeface, and format. They direct and by the code for the condition on line 24E on the guide the coder to the appropriate code and should be strictly CMS-1500 form. adhered to. Each publisher uses these same conventions, and 7. For ambulatory or outpatient surgical proce- many add more to assist coders in providing the most com- dures, code the diagnosis applicable to the pro- plete and accurate reason for the encounter. For example, cedure. If the postoperative diagnosis is differ- when you locate the word itch, you will find “see pruritus,” ent from the preoperative diagnosis, use the the medical term for severe itching. This is a helpful tool for postoperative diagnosis. coders who are unfamiliar with medical terminology. 286 Section II ■ The Administrative Assistant

Conventions Index to Disease Example Braces { } These are used in the Tabular List to 478.1 Other diseases of nasal cavity and sinuses connect a series of terms to a common stem. Each term Abscess on the left of the brace is incomplete without one of the Necrosis Of nose (septum) terms to the right of the bracket. Ulcer } Brackets [ ] Brackets enclose synonyms, alternate 422.92 Septic myocarditis wording, or explanatory phrases Myocarditis, acute or subacute: Colon : A colon is used after an incomplete term that Pneumococcal needs one or more of the modifiers that follow to make Staphylococcal it assignable to a given category Use additional code to identify infectious Parentheses ( ) Parentheses enclose supplementary organism [e.g., Staphylococcus 041.1] words that may be present or absent in the statement of See above example 478.1 (septum) may or may not be a disease or procedure, without affecting the code present in the diagnosis given. number to which it is assigned. Infection NEC (not elsewhere classifiable) Alerts the coder that Streptococcal NEC 041.00 the specified form of the condition is classified differently. Group Codes following NEC should be used only when the A 041.01 coder lacks the information necessary to code the term B 041.02 in a more specific category. As soon as the bacterium is identified, code for specific NOS (not otherwise specified) The coder should infection. continue to look for a more specific code At the time of the service, it has not been established Note Used to define terms and give coding whether a neoplasm is benign or secondary, for example. instructions. Found most often with list of fifth digits. Remember, you are coding for a date of service with the “Includes” Indicates separate terms as adjectives that information documented for that date of service. further modify sites and conditions or to further define Allergic rhinitis (nonseasonal) or give examples of the content of a certain category. INCLUDES 477 Allergic rhinitis (seasonal) “Excludes” A box with “excludes” in italics draws the Hay fever reader’s attention to instructions that direct the coder EXCLUDES Allergic rhinitis with asthma (bronchial) to the proper code. This convention is found in the (493.0) Tabular List. Itch (see also Pruritus) 698.9 “See,” “See Also,” and “See Category” Direct the See 422.92 examples above. coder to other terms or sections that should be 362.72 Retinal dystrophy in other systemic disorders considered. ALWAYS follow these instructions. and syndromes “Use additional code” This directs the coder to add Code first underlying disease, as: another code to further explain and give the third-party Bassen-Kornzweig syndrome (272.5) payer a better understanding of a diagnosis. Refsum’s disease (356.3) “Code First Underlying Disease” This direction is used in the tabular list when a reason for an encounter results from another disorder. The coder is instructed to indicate the underlying disease that caused the current problem or symptom that brought the patient to the office.

F IGURE 17–3. Conventions used in ICD-9.

Main Term is cyst. Find the condition, not the location. Remember the exceptions to the rules of using the main term. When trying to locate a diagnosis with more than one word, look first under the main term or condition. Often, a diagno- Fourth and Fifth Digits sis may be an eponym (e.g., Ménière’s disease or syndrome). These terms can be found under the main term dis- In many instances, a fourth digit has been added to a cate- ease or syndrome. In the diagnosis breast cyst, the main term gory to provide more detail, or specificity. These are subcat- Chapter 17 ■ Diagnostic Coding 287 egory codes. Some codes also have a fifth digit because of Box 17-4 the need to code to a higher specificity. For example, diabetes mellitus is category 250. It is necessary to use one of the fourth-digit subcategories to indicate the specific com- STEPS IN LOCATING plications that may accompany the diabetes and then add a A DIAGNOSTIC CODE fifth digit to indicate whether the diabetes is insulin depend- 1. Choose the main term within the diagnostic state- ent or non–insulin dependent. Those codes requiring a fifth ment. digit are identified in both Volumes 1 and 2. Incomplete cod- 2. Locate the main term in Volume 2. ing here affects reimbursement and causes data errors. Fig- 3. Refer to all notes and conventions under the main ure 17-4 shows samples of fifth-digit classifications from the term. ICD-9-CM, Volumes 1 and 2. The code 807.1 tells the third- 4. Find the appropriate indented subordinate term. party payer that the patient was seen for an open fracture of 5. Follow any relevant instructions, such as “see a rib. The fifth digit is added to describe how many ribs. A also.” patient who fractured two ribs would be assigned the code 6. Confirm the selected code by cross-referencing 807.12. This gives a more thorough picture of the patient’s to Volume 1. Make sure you have added any problem and enables the payer to determine whether the fourth or fifth digits necessary. treatment is medically necessary. 7. Assign the code.

Primary Codes ratory work would be seen as medically unnecessary, and In outpatient coding, the primary diagnosis is simply the the physician would not be reimbursed. patient’s chief complaint or the reason the patient sought medical attention today. It may be a routine follow-up visit, or there may be a new problem. The primary code is listed Late Effects first on the CMS-1500 (Box 17-4). Late effects are symptoms or conditions arising from an acute illness. The effects are present after treatment for the When More Than One Code Is Used acute illness or injury has ended. Proper coding sequence requires that you list the code number identifying the In many cases, more than one code is used for a single pa- residual or current condition first, with the code number tient visit. When patients have more than one diagnosis, it identifying the cause or original illness or injury listed sec- is necessary to convey an accurate picture of the patient’s ond. Key words used in the patient’s medical records total condition. For example, an elderly patient may have defining late effects include late, due to an old injury, due the following diagnoses listed each time she visits the doc- to a previous illness/injury, due to an illness or injury tor: degenerative arthritis, type II diabetes mellitus, macu- occurring a year or more ago, sequela of... , as a result lar degeneration, hypertension, and pernicious anemia. If of... , resulting from... , and so on. Patients who are sta- any of these conditions is related to or affects her treatment, tus post cerebrovascular accident (CVA) may have resid- they should be listed as supplementary information. If she ual effects from their original stroke, for example, and may visits the doctor because she has influenza and her other di- have a diagnosis of left hemiparesis as a result of CVA 3 agnoses are not addressed at the visit, it is not necessary to years ago. Figure 17-6 is a sample listing of a late effect list all the diagnoses given. The primary diagnosis is her from the ICD-9-CM. reason for coming to the office (symptoms of influenza). But the fact that she is diabetic will affect her treatment and makes her visit medically necessary. Multiple codes should be sequenced with the proper service or procedure code on the proper line of the CMS-1500. Figure 17-5 shows the proper sequencing for another patient’s CMS-1500. On LEGAL TIP line 1 of Section 24 on the CMS-1500 you place the code and charge for the visit. In Block 24E, the diagnosis code Remember that the ICD-9 codes placed on the CMA- for the ankle injury appears first because that is what 1500 are confidential and should be protected as much brought the patient to the office today. One Line 2 of 24A, as any other medical information. Forms left lying in the laboratory work is listed but is also referenced to the di- common areas in the office may be seen by other pa- agnosis on Line 21, Item 2, which is the proper code for the tients. Keep printers and copies of these forms in a pri- patient’s diabetes; this is referenced to Item 2 on Line 24. vate place and share the diagnosis codes only with those If the patient did not have diabetes, the laboratory work who need the information to carry out their duties. Pa- would not be considered reasonable for a patient with an tients have the right to keep their diagnoses private. ankle injury. If this procedure were not followed, the labo- 288 Section II ■ The Administrative Assistant

B F IGURE 17–4. Samples of fifth-digit classifications from ICD-9-CM. (A) Volume 1. (B) Volume 2. Chapter 17 ■ Diagnostic Coding 289

F IGURE 17–5. Sample CMS-1500 claim form indicating proper sequencing. 290 Section II ■ The Administrative Assistant

F IGURE 17–6. Sample section of late effects in ICD-9-CM. (A) Volume 1. (B) Volume 2.

Coding Suspected Conditions physician may indicate “rule out,” “suspected,” or “proba- ble.” For example, a patient who comes in complaining of In the inpatient setting, coders list conditions after the pa- headache may be sent for magnetic resonance imaging tient’s testing is complete. In other words, they are coding (MRI) of the head because the physician suspects a serious with complete information. In outpatient settings, however, disorder. On the patient’s encounter form, the physician may the coder reports the reason for the patient visit as it occurs. list the diagnosis as “rule out brain tumor.” It is not accurate When filing claims, the coder is limited by the information to code the visit as brain tumor before it is confirmed by and documentation on hand at the time of the patient visit. If MRI. On this first visit to the physician’s office, the reason at the end of the visit the diagnosis is not confirmed, the for being seen is headache. The patient’s symptom Chapter 17 ■ Diagnostic Coding 291

more codes and will be used by every type of health care provider for all encounters, including hospice and home health care. The new codes are alphanumeric, but the format WHAT IF of the index is similar to the ICD-9-CM. Two new chapters relating to disorders of the eye and the ear are being added to You need to code a condition described as acute, the ICD-10. Computer software will be revised, and the ICD- chronic, or both. What code should you use? 9-CM code books will be obsolete. When a particular condition is described as both acute and chronic, code it according to the subentries in the al- Checkpoint Question phabetic index (Volume 2) for the condition. If there are 9. List two reasons for a chart audit. separate entries listed for acute, subacute, and chronic, use both codes. The first code listed should be for the acute condition, the reason the patient came to the office today. Respiratory and orthopedic conditions tend to be acute and chronic. That is, a patient with emphysema CHAPTER SUMMARY will always have underlying symptoms of progressive disease, but during the spring, pollen may aggravate the Medical outpatient diagnostic coding involves the use of condition and cause acute breathing problems. numbers to describe diseases, injuries, and other reasons for seeking medical care. ICD-9-CM provides an index to report and track diseases. Diagnostic coding is linked to reimbursement because it assures that the physician’s (headache) is the only confirmed reason for the encounter at service or procedure was medically necessary. As a this point. On the second visit to the doctor, the MRI has con- medical assistant, you must understand the format and firmed a glioma in the frontal lobe. For the second and all guidelines for assigning a code or reason for each en- subsequent visits, glioma is coded as the reason for the encounter, treatment, and/or service. counter. Figure 17-2 shows a page from the ICD-9-CM that includes many of the symptom codes. Critical Thinking Challenges Checkpoint Question Tom Barksdale has been seen by the physician for con- 8. Before a definitive diagnosis is made, what is trolled non–insulin-dependent type 2 diabetes mellitus for coded? about 10 years. While being seen for a routine check of his blood sugar, he complains of numbness and tingling in his Documentation Requirements left lower leg and foot. An x-ray of both legs is performed, since poor circulation in the extremities can be a complica- As discussed throughout this chapter, you should choose the tion of diabetes. The x-ray confirms the diagnosis of periph- code assigned to any given claim for a service or procedure eral neuropathy. based on the documentation available in the patient’s record at the time of the service. An audit is conducted by the gov- 1. Which ICD-9 code should be listed with the office ernment, a managed care company, and a health care organ- visit? ization to determine compliance and to detect fraud. Re- 2. Which code indicates the reason for the x-ray? member, if it’s not in the chart, it did not happen. Auditors 3. Which code should be placed on the CMA-1500 first verify the codes used based on information recorded in the as the primary diagnosis or reason for the visit? chart on the date of service. Answers:

THE FUTURE OF DIAGNOSTIC 1. 250.60 CODING: INTERNATIONAL 2. 337.1 CLASSIFICATION OF DISEASES, 3. 250.60 TENTH REVISION Answers to Checkpoint Questions A new edition of the ICD, the International Classification of Diseases, Tenth Revision (ICD-10), is scheduled to be intro- 1. Medical necessity means a particular service or proce- duced sometime between 2003 and 2005. The WHO is re- dure is reasonable. sponsible for revising the ICD to improve the quality of data 2. The three volumes of ICD-9-CM are Volume 1, the input into clinical databases. The ICD-10-CM will include Tabular List of Diseases; Volume 2, the Alphabetic 292 Section II ■ The Administrative Assistant

Index of Diseases; and Volume 3, the Tabular List services must be coded with the patient’s symptoms and Alphabetic Index of Procedures. at the time he or she was seen. 3. The World Health Organization must approve any 9. Chart audits are conducted to assess compliance and changes in the ICD-9-CM system. to detect fraud. 4. Inpatient refers to a patient who is admitted to the hospital for a stay anticipated to be longer than a day. Websites An outpatient is one who is seen in the physician’s office or for 1-day surgery and will stay in the inpatient World Health Organization facility for less than 24 hours. www.who.int 5. ICD-9-CM is updated annually in October. Health and Human Services 6. E-codes are used to provide information to (1) indus- www.hhs.gov try, (2) insurance underwriters, (3) national safety Centers for Medicare & Medicaid programs, and (4) public health agencies and others www.cms.gov concerned with injuries and poisonings. American Health Information Management Association 7. V-codes are used to report reasons for receiving serv- www.ahima.org ices other than illness. American Hospital Association 8. Before a definitive diagnosis is assigned to a patient, www.aha.org