2021 allergy Medicare E&M coding distribution

| | December 19, 2022

2021 allergy Medicare E&M coding distribution

Medicare overhauled the rules for Evaluation and Management (E&M) coding beginning in 2021, with E&M codes now based on time or medical decision-making. We were curious: how did allergist coding patterns change with the new rules? Medicare publicly reports specialty-specific E&M utilization data each year, which they use to identify providers who are overcoding. But this data can also tell us how allergy/immunology E&M coding patterns change over time, as well as help you see how your coding distribution for E&M services compares to other allergists.

2021 and 2020 Medicare E&M code usage for allergy/immunology is summarized below. Coding pattern shifts were minor during the first year of the coding change as allergists learned how to incorporate the new rules. For new patient visits, we saw a very slight increase in the percentage of level 4 and 5 visits and a two-percentage point decrease in the number of level 3 visits. The most common code used by allergists in 2021 was a level 4 at 58.5% of the time. Level 3 was the next most common, at 32.2%. Level 5 use inched up to 7.7%.


Allergy/Immunology Medicare E&M Distribution – New Patients
New Patient E&M Code 2021 Usage 2021 Utilization% 2020 Usage 2020 Utilization %
99202 2,704 1.6% 3,055 2.2%
99203 53,914 32.2% 46,539 34.1%
99204 97,992 58.5% 77,711 57.0%
99205 12,810 7.7% 9,097 6.7%
Total 167,420 100.0% 136,402 100.0%
Source: Medicare Part B Physician/Supplier National Data CY2020, E&M Codes for Allergy/Immunology and

Coding shifts for existing patient visits were also minor. Level 4 usage increased to 42.8% in 2021 from 40.0% in 2020 and came closer to tying level 3 for the most common E&M code used by allergists. Level 3 coding dropped from 48.4% in 2020 to 45.6% in 2021. Levels 1, 2 and 5 continue to be used infrequently.


Allergy/Immunology Medicare E&M Distribution – Existing Patients
Existing Patient E&M Code 2021 Usage 2021 Utilization % 2020 Usage 2020 Utilization %
99211 26,253 3.7% 26,511 4.0%
99212 32,403 4.6% 31,185 4.8%
99213 320,917 45.6% 317,825 48.4%
99214 301,277 42.8% 262,630 40.0%
99215 23,459 3.3% 17,980 2.7%
Total 704,309 100.0% 656,131 100.0%
Source: Medicare Part B Physician/Supplier National Data CY2020, E&M Codes for Allergy/Immunology and

It will be interesting to see how these patterns change further, now that allergists/immunologists are becoming more familiar with the new E&M coding rules.

You may want to pull your own historical coding data from your practice management system to see how it compares to the average Medicare coding distribution for allergists/immunologists. Keep in mind, however, that every practice has a different demographic of patients, and your own experience, especially with non-Medicare patients, may not be directly comparable to the Medicare average.

If you or your billing staff needs an overview or refresher on allergy/immunology coding, we encourage you to check out the College’s updated Coding Toolkit. We have explanations of the 2021 E&M coding rules, plus expert advice on coding for 95165, allergy testing, immunotherapy, procedures, OIT and more. Our Coding FAQ database should be the first place you look when you have an allergy coding question!

Special thanks to Robert Ellis, the CFO of the Carolina Asthma & Allergy Center, for sharing the 2021 data cited in this article.