QUEST Integration – Diagnosis Coding

Original Effective Date:

08/01/1994

Current Effective Date:

01/01/2015

Incorrect diagnosis coding is a common reason for processing delays. Your adherence to the guidelines below will help assure that your claims are processed quickly and accurately.

In addition, diagnosis codes are a key data type used to identify trends in utilization. Therefore, the diagnoses must be accurately coded.

Correct diagnosis coding begins with selecting the appropriate diagnosis code(s) from the most recent edition of the ICD-10-CM coding manual. HMSA accepts diagnosis codes entered to the fifth position. The following guidelines will help you choose the most appropriate code:

• Select the most specific diagnosis code available to describe the patient’s condition. For example, do not select cystitis (595) when the patient has chronic interstitial cystitis (595.1) or cystitis caused by an abscess of the bladder (595.89). Do not add zeros after the decimal to artificially create five positions.
• List a secondary diagnosis only when it has a bearing on the patient’s current medical condition and treatment. For example, if the patient’s diabetes complicates or otherwise affects a physician’s treatment of his foot ulcer, both diagnoses should be listed on the claim. The diagnosis most closely linked to the patient’s current complaint should be listed in the primary position.
• Do not list conditions for which the patient was previously treated and has since recovered, or that have no bearing on the patient’s current complaint and treatment.
• For diabetes and certain other conditions, ICD-10-CM requires that the underlying disease be listed as the primary diagnosis, and manifestations of the disease be listed as secondary diagnosis.
• Be aware that the ICD-9-CM manual classifies some diagnoses as appropriate only for patients of a specific age or gender. It is important to read the text surrounding the diagnosis and to note specific symbols for age and gender as well as exclusions. For example, diagnosis 773.0 (hemolytic disease due to Rh isoimmunization) includes the age indicator A:0, meaning that this diagnosis applies to newborns only. This code should not be used to code the diagnosis for a mother who is undergoing ultrasound prior to the birth of her baby. The correct diagnosis to enter for the mother is 656.1 (Rhesus isoimmunization).

If you do not have a current copy of the ICD-10-CM manual, we urge you to purchase one and obtain an updated version every two years. Please refer to Code Books in the appendix section for information on ordering the current edition.

Claims Filing Information

In addition to selecting the most appropriate diagnosis for your patient, it is important to place the codes in block 21 of the HCFA 1500 claim form correctly. For example, if a patient was seen by the doctor for ulcers on his feet, and the doctor knows that the patient’s condition is a complication of his diabetes, the claim might be coded as follows:

• The primary diagnosis would be 250.7 (diabetes with peripheral circulatory disorders).
• An appropriate secondary diagnosis would be 707.1 (ulcer of lower limbs).
• An office visit to treat the patient’s foot ulcer would reference the secondary diagnosis, while a urinalysis done to test the patient’s glucose level would correspond more closely with the primary diagnosis and should be coded accordingly.

If the supporting reference number (1, 2, 3, or 4) from block 21 is not entered in column 24E, the primary diagnosis will be used to support all of the services rendered, which may result in benefits being denied or processed incorrectly for individual procedures.

Please refer to the example below for the appropriate use of diagnosis code reference numbers.

Example:

Revision History