Article by:

Valerie M. Slee, RN, BSN, TMS Chair

Susan Jennings, PhD, TMS Research Chair

ICD-10-CM Code Proposals for Mast Cell Disorders-Background

Back as far as 2009, TMS was involved in discussions with the American Academy of Allergy, Asthma and Immunology (AAAAI) Mast Cell Disorders Committee about trying to obtain an organized coding hierarchy for mastocytosis and mast cell activation syndrome (MCAS). At the time, we had a solid set of World Health Organization (WHO) diagnostic criteria for mastocytosis, but no such criteria for MCAS. In 2012, a Consensus Committee Proposal for mast cell activation syndrome was published.¹ We finally had a foundation upon which to develop and submit codes for a newly described entity, mast cell activation syndrome. We also prepared to completely revise existing codes for mastocytosis, some of which existed, but which were spread all over the coding manual and lacked important breakdown by subvariant.

For extended periods during 2013 and early 2014, much of our TMS Research Committee time, as well as Valerie’s time as Chair during those years, was spent on this initiative. It was, to say the least, an enormous undertaking. We had the support of the AAAAI Mast Cell Disorders Committee, and from that group of esteemed experts, a sub-committee of volunteers for this project came forward: Arnold Kirshenbaum, MD, Co-Chair; Catherine Weiler, MD, PhD, Co-Chair; Joseph Butterfield, MD; Mariana Castells, MD, PhD; and Cem Akin, MD, PhD. Others volunteered their time and expertise while not being able to commit to serving on the committee. From TMS, we had Susan Jennings, PhD, Research Co-Chair and Chair of TMS efforts on this initiative; Valerie Slee, RN, BSN, TMS Chair; Nancy Russell, PhD, Research Co-Chair; and Mishele Cunningham, RN, BSN, PHN, Education Chair. Numerous phone calls were made to the Centers for Disease Control and Prevention (CDC)/ National Center for Health Statistics (NCHS) even before we began the very complex outline. The first step was gathering all of any existing codes that in any way pertained to a mast cell disorder.  The codes were scattered all over the place, some in rather unexpected categories. From there, we began our comprehensive outline for MCAS, because the CDC/NCHS only invited coding proposals for newly described diseases/disorders at that point in time. We began refining our coding proposal and began working with a physician contact from the CDC/NCHS. We very quickly learned some critical points: that any code previously established or inserted by the WHO would not be deleted completely, and that most codes would include categories called other and/or unspecified. The CDC ICD-10 CM instruction manual describes that codes titled “other” or “other specified” are for use when a patient’s medical record provides detail for which a specific code doesn’t exist. Codes titled “unspecified” are for use when the information in the medical record is insufficient to assign a more specific code. These two categories ended up giving us the flexibility we needed to include future types of MCAS that may arise; indeed, soon after we submitted the coding proposal, data on familial alpha-tryptasemia was published.² For now, medical professionals could potentially use one of these codes to obtain coverage for this diagnosis as needed, until another coding revision occurs.

After developing our outline, we gathered research articles to support each of our coding submissions and its place within the hierarchy we were proposing. We spent hundreds of hours on this work, carefully justifying each code and reviewing our rational with our CDC/HCHS contact.  We learned which place to the right of the decimal point represented what category of disease or symptom. Even though we were only working on MCAS at this point, we made a draft comprehensive outline, inclusive of mastocytosis, in order to ultimately end up with a very cohesive coding hierarchy. We thought that once the codes for MCAS were submitted, proposing the codes for mastocytosis would therefore be a cinch! Boy, were we wrong!

In March 2014, we submitted the coding proposal for MCAS. The codes were implemented in October, 2016, and we were able to announce this during our 2016 TMS Conference in Orlando, Florida! We sure had something to celebrate, because two years of waiting for implementation requires a lot of patience!

Back to March, 2014. Once the codes for MCAS were submitted, we started working on the codes for mastocytosis. This turned out to be much more complex than we thought it would be. Members of the committee wanted to approach this from many different angles. Emails flew back and forth for months. We tried very hard to integrate all of the changes and recommendations that everyone suggested, but as the deadline approached, we just could not make it work. Finally, we called everyone on the coding committee and asked for a 5 PM meeting that day in July, 2014. Everyone agreed, and showed up pretty much on time! This was an amazing feat for busy practicing physician researchers in different time zones with so little notice, and speaks to their dedication. We worked hard as a group for over an hour and finalized the coding document! Once it was approved by the AAAAI Board of Directors, who cosponsored the initiative, we sent it to Joseph Butterfield, MD, who was the Chair at the time of the AAAAI Mast Cell Disorders Committee, and he submitted it on behalf of the committee, TMS and the AAAAI.

Although we were instructed to closely adhere to the WHO classifications for mastocytosis, were told we could not remove an existing code completely, and needed to incorporate the expanded coding requirements of ICD-10-CM, resulting in a large number of codes being proposed. The primary feedback on our mastocytosis coding proposal was related to concern regarding the large number of codes for a rare set of disorders. We asked for specific input on our proposal so we could continue to work on revising the mastocytosis codes, but did not receive any status updates for three years, from July 2014 to October 2017, other than instructions that if the CDC/NCHS needed additional consultation with our committee, they would contact us. We had decided to start from scratch and revise all the codes for mastocytosis, a project we would undertake in 2018. Then, on October 1, 2017, the CDC/NCHS announced the new codes which had been implemented, and among them were new codes for mastocytosis! They accepted many of the coding categories we proposed, but simplified the codes within them tremendously.

This is a huge achievement, and one that all of us on the coding committee are very proud of. Coding for mastocytosis, MCAS and other newly identified mast cell diseases may require some revision, or even new coding proposals in the future, but overall we now have very workable codes. These codes facilitate patients getting insurance coverage, applying for disability, and obtaining the medications they need. They also enhance recognition of these diseases, and increase their credibility.

Below we have copied and pasted the ICD-10 CM Codes for you (from www.icd10data.com, visited in October 2017) so that you can see them clearly. If a code has a statement that it is non-billable, that means one has to select one of the more specific codes listed below the main code for billing purposes.

We hope this helps you to understand the process we went through to obtain ICD-10 CM codes for mast cell disorders!

2017/18 ICD-10-CM Diagnosis Codes for Mast Cell Disorders

The information below was taken directly from the www.idc10data.com website (visited October 2017), unless otherwise specified. Additional information on these codes can be obtained on that website, through their search mechanism, using a specific code or diagnosis type, or through the CDC/NCHS website at www.cdc.gov/nchs/icd/icd10cm.htm.

NOS = “Not otherwise specified”

CODES BELOW ARE FOR THE UNITED STATES

2017/18 ICD-10-CM Diagnosis Code Q82.2

Congenital cutaneous mastocytosis

2016; 2017; 2018 – Revised Code; Billable/Specific Code; POA Exempt

• Q82.2 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM Q82.2 is a revised 2018 ICD-10-CM code that becomes effective on October 1, 2017.
• This is the American ICD-10-CM version of Q82.2 – other international versions of ICD-10 Q82.2 may differ.

Applicable To

• Congenital diffuse cutaneous mastocytosis
• Congenital maculopapular cutaneous mastocytosis
• Congenital urticaria pigmentosa

Type 1 Excludes

• cutaneous mastocytosis NOS (D47.01)
• diffuse cutaneous mastocytosis (with onset after newborn period) (D47.01)
• malignant mastocytosis (C96.2-)
• systemic mastocytosis (D47.02)

2017/18 ICD-10-CM Diagnosis Code D47.0

Mast cell neoplasms of uncertain behavior

2016; 2017; 2018 – Deleted Code; 2018 – New Code; Non-Billable/Non-Specific Code

• D47.0 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail. (SEE below)
• ICD-10-CM D47.0 is a new 2018 ICD-10-CM code that became effective on October 1, 2017.
• This is the American ICD-10-CM version of D47.0 – other international versions of ICD-10 D47.0 may differ.

Type 1 Excludes

• congenital cutaneous mastocytosis (Q82.2-)
• histiocytic neoplasms of uncertain behavior (D47.Z9)
• malignant mast cell neoplasm (C96.2-)

2017/18 ICD-10-CM Diagnosis Code D47.01 

Cutaneous mastocytosis

2018 – New Code; Billable/Specific Code

• D47.01 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM D47.01 is a new 2018 ICD-10-CM code that becomes effective on October 1, 2017.
• This is the American ICD-10-CM version of D47.01 – other international versions of ICD-10 D47.01 may differ.

Applicable To

• Diffuse cutaneous mastocytosis
• Maculopapular cutaneous mastocytosis
• Solitary mastocytoma
• Telangiectasia macularis eruptiva perstans
• Urticaria pigmentosa

Type 1 Excludes

• congenital (diffuse) (maculopapular) cutaneous mastocytosis (Q82.2)
• congenital urticaria pigmentosa (Q82.2)
• extracutaneous mastocytoma (D47.09)

2017/18 ICD-10-CM Diagnosis Code D47.02 

Systemic mastocytosis

2018 – New Code; Billable/Specific Code

• D47.02 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM D47.02 is a new 2018 ICD-10-CM code that becomes effective on October 1, 2017.
• This is the American ICD-10-CM version of D47.02 – other international versions of ICD-10 D47.02 may differ.

Applicable To

• Indolent systemic mastocytosis
• Isolated bone marrow mastocytosis
• Smoldering systemic mastocytosis
• Systemic mastocytosis, with an associated hematological non-mast cell lineage disease (SM-AHNMD)

2017/18 ICD-10-CM Diagnosis Code D47.09

Other mast cell neoplasms of uncertain behavior

2018 – New Code; Billable/Specific Code

• D47.09 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM D47.09 is a new 2018 ICD-10-CM code that became effective on October 1, 2017.
• This is the American ICD-10-CM version of D47.09 – other international versions of ICD-10 D47.09 may differ.

Applicable To

• Extracutaneous mastocytoma
• Mast cell tumor NOS
• Mastocytoma NOS
• Mastocytosis NOS

2017/18 ICD-10-CM Diagnosis Code C96.2

Malignant mast cell neoplasm

2016; 2017; 2018 – Deleted Code; 2018 – New Code; Non-Billable/Non-Specific Code

• C96.2 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.(SEE below)
• ICD-10-CM C96.2 is a new 2018 ICD-10-CM code that became effective on October 1, 2017.
• This is the American ICD-10-CM version of C96.2 – other international versions of ICD-10 C96.2 may differ.

2017/18 ICD-10-CM Diagnosis Code C96.21 

Aggressive systemic mastocytosis

2018 – New Code; Billable/Specific Code

• C96.21 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM C96.21 is a new 2018 ICD-10-CM code that becomes effective on October 1, 2017.
• This is the American ICD-10-CM version of C96.21 – other international versions of ICD-10 C96.21 may differ.

2017/18 ICD-10-CM Diagnosis Code C96.22

Mast cell sarcoma

2018 – New Code; Billable/Specific Code

• C96.22 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM C96.22 is a new 2018 ICD-10-CM code that becomes effective on October 1, 2017.
• This is the American ICD-10-CM version of C96.22 – other international versions of ICD-10 C96.22 may differ.

2017/18 ICD-10-CM Diagnosis Code C96.20

Malignant mast cell neoplasm, unspecified

2018 – New Code; Billable/Specific Code

• C96.20 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM C96.20 is a new 2018 ICD-10-CM code that became effective on October 1, 2017.
• This is the American ICD-10-CM version of C96.20 – other international versions of ICD-10 C96.20 may differ.

2017/18 ICD-10-CM Diagnosis Code C96.29

Other malignant mast cell neoplasm

2018 – New Code; Billable/Specific Code

• C96.29 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• ICD-10-CM C96.29 is a new 2018 ICD-10-CM code that became effective on October 1, 2017.
• This is the American ICD-10-CM version of C96.29 – other international versions of ICD-10 C96.29 may differ.

2017/18 ICD-10-CM Diagnosis Code C94.3 

Mast cell leukemia

2016; 2017; 2018; Non-Billable/Non-Specific Code

• C94.3 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail. (SEE below)
• The 2018 edition of ICD-10-CM C94.3 became effective on October 1, 2017.
• This is the American ICD-10-CM version of C94.3 – other international versions of ICD-10 C94.3 may differ.

2017/18 ICD-10-CM Diagnosis Code C94.31

Mast cell leukemia, in remission

2016; 2017; 2018; Billable/Specific Code

• C94.31 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• The 2018 edition of ICD-10-CM C94.31 became effective on October 1, 2017.
• This is the American ICD-10-CM version of C94.31 – other international versions of ICD-10 C94.31 may differ

2017/18 ICD-10-CM Diagnosis Code C94.32

Mast cell leukemia, in relapse

2016; 2017; 2018; Billable/Specific Code

• C94.32 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• The 2018 edition of ICD-10-CM C94.32 became effective on October 1, 2017.
• This is the American ICD-10-CM version of C94.32 – other international versions of ICD-10 C94.32 may differ.

2017/18 ICD-10-CM Diagnosis Code C94.30

Mast cell leukemia not having achieved remission

2016; 2017; 2018; Billable/Specific Code

• C94.30 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• The 2018 edition of ICD-10-CM C94.30 became effective on October 1, 2017.
• This is the American ICD-10-CM version of C94.30 – other international versions of ICD-10 C94.30 may differ.

Applicable To

• Mast cell leukemia with failed remission
• Mast cell leukemia NOS

2017/18 ICD-10-CM Diagnosis Code D89.4 

These codes went into effect October 1, 2016.

Mast cell activation syndrome and related disorders

2017 – New Code; 2018; Non-Billable/Non-Specific Code

• D89.4 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail. (SEE below)
• The 2018 edition of ICD-10-CM D89.4 became effective on October 1, 2017.
• This is the American ICD-10-CM version of D89.4 – other international versions of ICD-10 D89.4 may differ.

D89.4 Mast cell activation syndrome and related disorders

• 40 Mast cell activation, unspecified
• 41 Monoclonal mast cell activation syndrome
• 42 Idiopathic mast cell activation syndrome
• 43 Secondary mast cell activation
• 49 Other mast cell activation disorder

Type 1 Excludes

• aggressive systemic mastocytosis (C96.21)
• congenital cutaneous mastocytosis (Q82.2)
• (non-congenital) cutaneous mastocytosis (D47.01)
• (indolent) systemic mastocytosis (D47.02)
• malignant mast cell neoplasm (C96.2-)
• malignant mastocytoma (C96.29)
• mast cell leukemia (C94.3-)
• mast cell sarcoma (C96.22)
• mastocytoma NOS (D47.09)
• other mast cell neoplasms of uncertain behavior (D47.09)
• systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) (D47.02)

REFERENCES

1. Valent P, Akin C, Arock M, Brockow K, Butterfield JH, Carter MC, et al. Definitions, criteria and global classification of mast cell disorders with special reference to mast cell activation syndromes: a consensus proposal. Int Arch Allergy Immunol. 2012;157(3):215-25.
2. Lyons JJ, Yu X, Hughes JD, Le QT, Jamil A, Bai Y, et al. Elevated basal serum tryptase identifies a multisystem disorder associated with increased TPSAB1 copy number. Nat Genet. 2016 Dec;48(12):1564-9.