How to Establish Medical Necessity with Proper Medical Coding and Documentation

by | Posted: Nov 7, 2016 | Medical Coding

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Medicare defines medical necessity as: “health-care services or supplies needed to prevent, diagnose, or treat an illness, injury, condition, disease, or its symptoms and that meet accepted standards of medicine.” Experienced coders in medical coding companies are well aware of how to use the right diagnosis codes to report the service provided and inform the payer that it was medically necessary. Such services must be:

  • in accordance with generally accepted standards of practice
  • clinically appropriate in terms of type, frequency, extent, site and duration, and
  • considered effective for the patient’s condition or injury

Reporting the right ICD-10 and CPT codes supports the medical necessity of the procedure and tells the payer why the service was performed. The documentation must include the diagnosis for all procedures that are performed as well as the diagnosis for each diagnostic test ordered.

A report published by the American Association of Professional Coders (AAPC) reminds physicians that establishing medical necessity is important for even low-level evaluation and management (E/M) visits such as outpatient visits. In such cases, the presenting problem may be minimal. Outpatient visit essentials include:

  • Documentation that supports the level of service billed
  • Notes that contain all the elements required to support the level of service selected
  • Clearly established medical necessity, that is, the note should establish a clear reason for the visit, and how the assessment and plan are related to the reason for the visit

To prevent under-documenting, the documentation must portray all the elements of History, Exam and Medical Decision Making to indicate the level of service for the outpatient encounter.

Another point to note is when documenting services provided for patients with more than one diagnosis. Here, the ranking of the diagnoses must be done in a way as to represent medical necessity. According to ICD-10 guidelines, the primary or most serious diagnosis should be coded first as follows:

  • The main reason for the visit, or
  • The condition with the highest risk of morbidity/mortality that is being treated at the encounter

The additional diagnoses describing other conditions that the patient has should be listed after the primary condition. For instance, if a child comes in with diarrhea, fever, and vomiting, and is reported as unimmunized for all vaccines, the pediatrician should:

  • First code the symptoms of diarrhea, fever, dehydration, dry mouth, and vomiting
  • Determine if the patient has nausea and document it accordingly; there are different ICD-10 for nausea and vomiting, and/or if there is the presence of vomiting without nausea
  • Determine why the patient is not vaccinated and document accordingly

Expert coders in established medical coding service companies would also focus on the pediatrician’s definitive diagnosis and not on the presenting diagnosis to ensure appropriate reporting of medical necessity.

Knowing the coverage polices of various payers can help eliminate denied claims. The coverage policies of Medicare and private payers specify the diagnosis codes that support medical necessity for certain procedures as well as documentation requirements. Medical coding outsourcing is the best way to ensure submission of diagnosis codes that are supported by the medical record. With their in-depth knowledge about coding guidelines and payer rules, skilled medical coders can help physicians avoid claim denials and also educate them on submitting documentation to support the services rendered.

Meghann Drella

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