Coding MRSA

Methicillin-resistant Staphylococcus aureus infection (MRSA) is a serious worldwide health concern. MRSA can be either hospital or community acquired. Approximately 2 million hospital patients contract a hospital acquired infection each year at an approximate cost of $11 billion. Of these, approximately 126,000 are related to MRSA. Because the reporting of these conditions is important, coders should be familiar with the clinical circumstances surrounding MRSA and the related coding requirements.

Penicillin and cephalosporin antibiotics have traditionally been the treatment of choice for staphylococcus (staph) aureus infections. MRSA is a type of staph aureus that is resistant to these antibiotics. Because MRSA is so antibiotic resistant, it is often termed a superbug.

MRSA can be transmitted by direct and indirect contact. Some individuals have MRSA on their body but show no symptoms of infection; these people are called MRSA carriers and can transmit MRSA to others.

Risk factors for getting community acquired MRSA includes playing contact sports, sharing towels or other personal items or having any condition that suppresses the immune system such as HIV or cancer. People who live in unsanitary or crowded living conditions such as prisons or barracks are also at risk. Hospitalized patients are at risk of having healthcare workers and MRSA carriers accidently transfer MRSA to them. Unfortunately, hospitalized patients may also have IV lines or surgical incisions that can be easily contaminated. There are higher incidence rates of MRSA in nursing homes and long-term care facilities. Basically, direct contact with MRSA organisms on surfaces or on infected people are the highest risk factors for getting MRSA infections.

Symptoms of MRSA infections are variable; however, pus production is often found in the infected area such as boils, abscesses or impetigo. Cellulitis may be due to MRSA. These symptoms are most often found in community acquired but can also be found in hospital acquired MRSA. Patients may become septic. When antibiotic therapy fails, MRSA should be considered as a potential cause of the infection.

Once the antibiotic sensitivities are determined, the patient can be treated appropriately. The majority of serious MRSA infections are treated with two or more intravenous antibiotics that used in combination are often effective against MRSA. Antibiotics include vancomycin, Zyvox, Rifadin, Bactrim, Septra, etc. Minor skin infections may respond well to Bactroban.

Drainage of pus is the main surgical treatment of MRSA infections. Items that can serve as sources of infection, such as intravenous lines, should be removed. Any intervention needs to be followed by antibiotic therapy.

Unfortunately if the infection overwhelms the immune system, patients can still die from MRSA infection, even with appropriate antibiotic therapy. The earlier the diagnosis and therapy is instituted, the better the prognosis.

Coding MRSA

The following codes are used to identify and track MRSA infection and colonization:

038.12 Methicillin resistant Staphylococcus aureus septicemia

041.12 Methicillin resistant Staphylococcus aureus in conditions classified elsewhere and of unspecified site

482.42 Pneumonia due to methicillin resistant Staphylococcus aureus

V02.54 Carrier or suspected carrier of methicillin resistant Staphylococcus aureus

V12.04 Personal history of methicillin resistant Staphylococcus aureus

When a patient is diagnosed with an infection that is due to MRSA, and that infection has a combination code that includes the causal organism such as septicemia or pneumonia, assign the appropriate code for the condition. For example, septicemia due to MRSA is assigned code 038.12. Do not assign code 041.12 as an additional code, because code 038.12 includes the type of infection and the MRSA organism. Use an additional code from the 995.91-995.92 series when the infection has progressed to SIRS.

Code 041.12 is to be used as an additional code to identify the bacterial agent in diseases classified elsewhere and bacterial infections of unspecified nature or site. When there is documentation of a current infection due to MRSA, and that infection does not have a combination code that includes the causal organism, select the appropriate code to identify the condition along with code 041.12.

Assign code 482.42 for methicillin resistant pneumonia due to Staphylococcus aureus (MRSA).

Do not assign a code from subcategory V09.0, Infection with microorganisms resistant to penicillins, as an additional diagnosis.

Assign code V02.54 for patients documented as having MSRA colonization. Colonization means that MRSA is present without necessarily causing illness. A positive MRSA colonization test might be documented as “MRSA screen positive” or “MRSA nasal swab positive.” Colonization is not necessarily indicative of a disease process or as the cause of a specific condition unless documented as such by the provider.

If a patient is documented as having both MRSA colonization and infection, code V02.54 and a code for the MRSA infection may both be assigned.

Review the ICD-9-CM Official Guidelines for Coding on reporting MRSA and related conditions and take the following quiz.


1. A patient is admitted for treatment of an acute myocardial infarction. He tested positive for MRSA on routine nasal culture on admission to the ICU. During the hospitalization a central venous catheter was inserted. A few days later he became septic and was diagnosed with MRSA sepsis due to central venous catheter infection. What diagnoses codes should be assigned for this case?

a. 410.91, 038.12, V02.54

b.410.91, 999.31, 038.12, 995.91, V02.54

c. 410.91, 038.12, 995.91, V02.54

d. 410.91, 999.31, 038.12, V02.54

2: A 30-year-old female patient was admitted to the hospital and diagnosed with sepsis. She had delivered a baby via C-section 2 weeks ago. It was determined that she had sepsis due to MRSA from the C-section wound. What diagnoses codes should be assigned for this case?

a. 674.34, 670.24, 041.12

b. 674.34, 670.24, 041.12, 995.91

c. 670.24, 041.12, 995.91

d. 038.12, 995.91, 670.24

This month’s column has been prepared by Cheryl D’Amato, RHIT, CCS, director of HIM, hospital solutions, and Melinda Stegman, MBA, CCS, clinical technical editor, Ingenix.

Coding Clinic is published quarterly by the American Hospital Association.
CPT is a registered trademark of the American Medical Association.


1. b: Assign code 410.91, Acute myocardial infarction, of unspecified site, initial episode of care, as the principal diagnosis. In addition, assign codes 999.31, Infection due to central venous catheter; 038.12, Methicillin resistant Staphylococcus aureus septicemia; 995.91, Sepsis; and V02.54, Carrier or suspected carrier of infectious diseases, Methicillin resistant Staphylococcus aureus.

2. a: Assign code 674.34, Other complications of obstetrical surgical wounds, as the principal diagnosis. Assign also codes 670.24, Puerperal sepsis, postpartum condition or complication; and 041.12, Methicillin resistant Staphylococcus aureus for the MRSA puerperal sepsis. The sequencing is based on the Official Guidelines for Coding and Reporting instructions regarding puerperal sepsis and postprocedural sepsis.

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