A single code used to classify two diagnoses, a diagnosis with a secondary condition, or a diagnosis with an associated complication.
Indicates that a diagnosis is still possible. Diagnoses qualified by the term rule out are coded as if esbablished for INPATIENT espisodes of care.
Indicates that a diagnosis once considered likely is no longer possible. A DIAGNOSIS DESCRIBED AS "RULED OUT" IS NEVER CODED! If an alternative condition has been identified, that diagnosis should be coded; otherwise, a code for the presenting symptom or other precursor condition should be assigned.
The First Coding Principle
Both the Alphabetic Indexes and the Tabular Lists must be used to locate and assign appropriate codes. No matter how experienced a coder is, don't rely on memory alone.
Assign Codes To The Highest Level of Detail:
Second Basic Principle
Codes must be used to the highest number of digits available. Follow these steps: Assign a three-digit disease code only when there are no four-digit codes within that category; Assign a four-digit code only when there is no fifth-digit subclassification for that category; Assign a fifth-digit for any category for which a fifth-digit subclassification is provided.
Code To Highest Level of Detail Exception
A zero should be added as a fourth digit to the rare code that requires a fifth digit when no fourth digit is provided.
Assign Residual Codes (NEC and NOS) As Appropriate (1)
The main term entry in the Alphabetic Index is usually followed by the code number for the unspecified condition. This code should never be assigned without a careful review of subterms to determine whether a more specified code can be located.
Assign Residual Codes (NEC and NOS) As Appropriate (2)
When the coder's review does not identify a more specific code entry in the index, titles and inclusion notes in the subdivisions under either the three-digit or the four-digit codes in the Tabular List should be reviewed. THE RESIDUAL NOS CODE SHOULD NEVER BE ASSIGNED WHEN A MORE SPECIFIC CODE IS AVAILABLE!
Assign Residual Codes (NEC and NOS) As Appropriate (3) Example 1
Refer to the Alphabetic Index in Volume 2 for nontraumatic hematoma of the breast, which is classified as 611.89. This is listed as "other" specified conditions of the breast. Even though the diagnosis is very specific, no separate code is provided.
Assign Residual Codes (NEC and NOS) As Appropriate (4) Example 2
Refer to the Alphabetic Index for phlebitis. Note that phlebitis, not otherwise specified, is assigned to code 451.9, Phlebitis, of unspecified site. Further review of the medical record reveals that this is a phlebitis of the lower extremity and therefore is more appropriately assigned to code 451.2, Phlebitis of lower extremities, unspecified.
Assign Combination Codes When Available (1)
A single code used to classify either two diagnoses, or a diagnosis with an associated secondary condition, or a diagnosis with an associated complication is called a combination code.
Assign Combination Codes When Available (2)
Only the combination code is assigned when that code fully identifies the diagnostic conditions involved or when the Alphabetic Index so directs. Examples: Acute cholecystitis w/cholelithiasis 574.00; Acute pharyngitis due to streptococcal infection 034.0; Bilateral recurrent femoral hernia w/gangrene 551.03; Glaucoma with increased episcleral venous pressure 365.82.
Assign Combination Codes When Available (3)
Occasionally, a combination code lacks the necessary specificity in describing the manifestation or complication; in such cases, an additional code may be assigned. Example: code 648x classifies anemia complicating pregnancy, delivery, or the peuperium. Because it does not indicate the type of anemia, an additional code can be assigned for this purpose.
Assign Multiple Codes As Needed
Multiple coding is the use of more than one code to fully identify the component elements of a complex diagnostic or procedural statement. A complex statement is one that involves connecting words or phrases such as "with," "due to," "incidental to," "secondary to," or similar terminology. When no combination code is provided, multiple codes should be assigned as needed to fully describe the condition regardless of whether there is advice to that effect.
Mandatory Multiple Coding (1)
The term "dual classification" is used to describe the required assignment of two codes to provide information about both a manifestation and the associated underlying disease. Mandatory multiple coding is identified in the Alphabetic Index by the use of a second code in brackets. The first code identifies the underlying condition and the second (in printed versions in italics) identifies the manifestation. Both codes must be assigned and sequenced in the order listed.
Mandatory Multiple Coding (2)
In the Tabular List the need for duel coding is indicated by the presence of a "use additional code" note with the code for the underlying condition and a "code first underlying condition" note with the manifestation code. Manifestation codes cannot be designated as the principal diagnosis, and a code for the underlying condition must always be listed first except for an occasional situations. A code in brackets in the Alphabetic Index can be used only as a secondary code for the specific condition or procedure indexed in this way.
Mandatory Multiple Coding (3) Examples
Ex 1: Diabetic type 1, on insulin, polyneuropathy 250.61 + 357.2 + V58.67 [V58.67 is not required for type 1 diabetes. However, Coding Clinic, Fourth Quarter 2004, p. 55, indicated that V58.67 may be assigned for type 1 diabetics, if desired. The Editorial Advisory Board felt that although V58.67 was not required.] Ex 2: Arthritis due to mumps 072.79 + 711.50
Discretionary Multiple Coding (1)
The "code", if applicable, any causal condition first" note indicates that multiple codes should be assigned only if the causal condition is documented as being present. Ex: ulcer of the lower limbs, except pressure ulcer 707.1x, requires that code to identify postphlebetic syndrome with ulcer 459.11 be assigned as the first-listed code or principal diagnosis but only if it is documented as being the cause of the ulcer.
Decretionary Multiple Coding (2)
The instruction to "use additional code" indicates that multiple codes should be assigned only if the condition mentioned is documented as being present. Ex: Reynaud's syndrome 443.0 requires an additional code to identify gangrene 785.4 but only when grangene is mentioned in the diagnosis or documented in the medical record. Ex: UTI 599.0 requires an additional code to identify the organism, if it is documented, such as positive culture of E. coli 041.49. Note: Acute Cystitis is an unspecified UTI.
Avoid Indiscriminate Multiple Coding (1)
Codes for symptoms or signs characteristic of the diagnosis and integral to it should not be assigned.
Avoid Indiscriminate Multiple Coding (2)
For Inpatient settings, codes are never assigned on the basis of findings of diagnostic tests, such as laboratory, X-ray, or ECG tests, unless the diagnosis is confirmed by the inpatient diagnosing physician. This differs from the Outpatient setting when coding encounters for diagnostic tests have been interpreted by the physician of the testing dept.
Avoid Indiscriminate Multiple Coding (3)
Diagnostic reports often mention such conditions as hiatal hernia, atelectasis, and right bundle branch block with no further mention to indicate any relevance to the care given. Assigning a code is inappropriate for reporting purposes unless the physician provides documentation to support the condition's significance for the episode of care.
Avoid Indiscriminate Multiple Coding (4)
Codes designated as unspecified ARE NEVER assigned when a more specific code for the same general condition is assigned. Ex: DM with unspecified complication would never be assigned when a code for diabetes with renal complication 250.4x is assigned for the same episode of care.
Code Unconfirmed Diagnoses As If Established (1)
When a diagnosis for an INPATIENT at the time of the discharge is qualified as: possible, probable, suspected, likely, questiontionable,?,rule out, consistent with, compatible with, indicative of, suggestive of, appears to be, and comparable with, the condition should be coded and reported as though the diagnosis were established. NOT SO WITH OUTPATIENTS!
Code Unconfirmed Diagnoses As If Established (2)
Caution should be used in coding unconfirmed diagnoses of conditions such as HIV infection/illness, epilepsy, AIDS, and multiple sclerosis as if they were established. Code only cases confirmed by physician documentation.
Borderline diagnoses are not the same as uncertain diagnoses. If a provider documents a borderline diagnosis at the time of discharge, the possible/probable guideline to code as if established would not apply in the situation. Instead, provider clarification is required for confirmation of the disease and if it is still not confirmed, a code for abnormal findings may be appropriate. Ex: borderline diabetes would be 790.2 Abnormal glucose. (Same for inpatient and outpatient espisodes).
Conditions Described As Both Acute And Chronic (1)
If separate subterms for acute (or subabcute) and chronic are listed at the same indention level in the Alphabetic Index, both codes are assigned, with the code for the acute condition sequenced first. (Note:subacute is coded as acute if no separate subterm is listed for subacute).
Conditons Described As Both Acute And Chronic (2)
When only one term is listed as a subterm, with the other in parentheses as a nonessential modifier, only the code listed for the subterm is assigned.
Conditions Described As Both Acute And Chronic (3)
In some cases, a combination code has been provided for use when the condition described as both acute and chronic. However, when there are no subentries for acute (subacute) or chronic, these modifiers are disregarded in coding the condition. Ex: Fibrocystic disease, breast 610.1.
Impending Or Threatened Conditon (1)
At the time of discharge or at the conclusion of an outpatient encounter if an impending or threatened conditon has actually occurred, it is coded as a confirmed diagnosis.
Impending Or Threatened Condition (2) Ex.1
The medical record shows a diagnosis of threatened premature labor at 28 weeks gestation. Review of the medical record indicates that a stillborn was delivered during the hospital stay. This is coded as 644.21, Early onset of labor, delivered, because the threatened conditon did occur.
Impending Or Threatened Condition (3)
If neither the impending/threatened condition nor a related condition occurred, refer to the Aphabetic Index and answer two questions: 1) Is the condition indexed under the main term threatened or impending?, 2) Is there a subterm for the impending/threatened under the main term for the condition? Ex: Patient is admitted with threatened abortion but the abortion is averted, the code 640.0x, Threatened abortion, is assigned because there is an index entry for "threatened" under the main term Abortion.
Impending Or Threatened Condition (4)
When neither term is indexed, the precursor condition that actually existed is coded. A code is not assigned for the condition impending or threatened. Ex: Patient is admited with a diagnosis of impending gangrene of the lower extremities, but the gangrene was averted. Because the gangrene did not occur and there is no index entry for impending gangrene, a code is assigned for the presenting situation that suggested the possibility of gangrene (i.e. symptom) such as redness or swelling of the extremity.
Report the Same Diagnosis Code More Than Once
Each code may be reported only once for an encounter. This applies both to bilateral conditions and to two different condtions classified to the same diagnosis code.
Late Effects Codes
A late effect is a residual condition that remains after the termination of the acute phase of an illness or injury. There is no set period of time that must elapse, they can occur at any time. Certain conditions due to trauma such as malunion, nonunion, and scarring are inherent late effects no matter how early they occur.
Identifying Late Effects (1)
Late effects include conditions reported as such or as sequela (residual) of a previous illness or injury. They can be inferred when a diagnositc statement includes terms like: Late, Old, Due to previous injury or illness, Following previous injury or illness, or Traumatic, unless there is evidence of current injury.
Identifying Late Effects (2) Examples
Hemiplegia due to previous cerebrovascular accicent; Malunion of fracture, right femur; Scoliosis due to old infantile paralysis; Keloid secondary to injury nine months ago; Mental retardation due to previous viral encephalitis.
Locating Late Effects Codes
Codes that indicate the cause of a late effect can be located by referring to the main term LATE and the subterm EFFECTS in the Alphabetic Index of Diseases and Injuries (Volume 2).
Late Effects: Two Codes Required (1)
Complete coding of late effect requires two codes: 1) Residual condition or nature of the late effect, sequenced first and 2) followed by the cause of the late effect unless the Tabular directs otherwise. If the late effect is due to an injury then a late effect E code should also be assigned.
Late Effect: Two Codes Required (2) Examples
Traumatic arthritis of right shoulder due to old fracture of right humerus 716.11 + 905.2 + E929.9; Paralysis of left leg due to old poliomyelitis 344.30 + 138; Scoliosis due to poliomyelitis at age twelve 138 (tabular directions say code this first) + 737.43
Late Effect: Two Codes Required (3) Exceptions 1
When the residual effect is not stated, the cause of the late effect code is used alone.
Late Effect: Two Codes Required (4) Exceptions 2
When no late effect code is provided in ICD-9-CM but the condition is described as being a late effect, only the residual condition is coded. Note: conditions described as due to previous surgery are not coded as late effects but are classified as history of or complications of previous surgery, depending on the specific situation.
Late Effect: Two Codes Required (5) Exceptions 3
When the late effect code has been expanded at the fourth or fifth-digit level to include the residual condition, only the cause of the late effect code is assigned. At present only category 438, Late effect of CVD, has been expanded this way.
Late Effect vs. Current Illness or Injury (1)
A late effect code is not used with a code for a current injury or illness of the same type, with one exception. A code from category 438, Late effect of cerebrovascular disease, is assigned as an additional code when a patient with residual effects from an earlier cerebrovascualr disease is seen because of current cerebrovascular disease.
Late Effect vs. Current Illness or Injury (2) Examples
A patient with residual aphasia due to subdural hemorrhage two years ago who is admitted because of acute cerebral thrombosis would have the following codes assigned:
434.00 Cerebral thrombosis, w/o mention of cerebral infarction, 434.11 Late effect of cerebrovascular disease, with speech and language deficits, aphasia