Department of Health and Human Services 

OFFICE OF 

INSPECTOR GENERAL 

JANET REHNQUIST 

Inspector General 

October 2002 

OEI-09-00-00530 

MEDICARE ANTIGEN PREPARATION 
Office of Inspector General

http://oig.hhs.gov 

The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-452, as 

amended, is to protect the integrity of the Department of Health and Human Services (HHS) 

programs, as well as the health and welfare of beneficiaries served by those programs. This 

statutory mission is carried out through a nationwide network of audits, investigations, and 

inspections conducted by the following operating components: 

Office of Audit Services 

The OIG's Office of Audit Services (OAS) provides all auditing services for HHS, either by 

conducting audits with its own audit resources or by overseeing audit work done by others. 

Audits examine the performance of HHS programs and/or its grantees and contractors in 

carrying out their respective responsibilities and are intended to provide independent 

assessments of HHS programs and operations in order to reduce waste, abuse, and 

mismanagement and to promote economy and efficiency throughout the department. 

Office of Evaluation and Inspections 

The OIG's Office of Evaluation and Inspections (OEI) conducts short-term management and 

program evaluations (called inspections) that focus on issues of concern to the department, the 

Congress, and the public. The findings and recommendations contained in the inspections 

reports generate rapid, accurate, and up-to-date information on the efficiency, vulnerability, and 

effectiveness of departmental programs. 

Office of Investigations 

The OIG's Office of Investigations (OI) conducts criminal, civil, and administrative 

investigations of allegations of wrongdoing in HHS programs or to HHS beneficiaries and of 

unjust enrichment by providers. The investigative efforts of OI lead to criminal convictions, 

administrative sanctions, or civil monetary penalties. The OI also oversees state Medicaid fraud 

control units, which investigate and prosecute fraud and patient abuse in the Medicaid program. 

Office of Counsel to the Inspector General 

The Office of Counsel to the Inspector General (OCIG) provides general legal services to OIG, 

rendering advice and opinions on HHS programs and operations and providing all legal support 

in OIG's internal operations. The OCIG imposes program exclusions and civil monetary 

penalties on health care providers and litigates those actions within the department. The OCIG 

also represents OIG in the global settlement of cases arising under the Civil False Claims Act, 

develops and monitors corporate integrity agreements, develops model compliance plans, 

renders advisory opinions on OIG sanctions to the health care community, and issues fraud 

alerts and other industry guidance. 
Department of Health and Human Services 

OFFICE OF 

INSPECTOR GENERAL 

JANET REHNQUIST 

Inspector General 

October 2002 

OEI-09-00-00530 

MEDICARE ANTIGEN PREPARATION 
Office of Inspector General

http://oig.hhs.gov 

The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-452, as 

amended, is to protect the integrity of the Department of Health and Human Services (HHS) 

programs, as well as the health and welfare of beneficiaries served by those programs. This 

statutory mission is carried out through a nationwide network of audits, investigations, and 

inspections conducted by the following operating components: 

Office of Audit Services 

The OIG's Office of Audit Services (OAS) provides all auditing services for HHS, either by 

conducting audits with its own audit resources or by overseeing audit work done by others. 

Audits examine the performance of HHS programs and/or its grantees and contractors in 

carrying out their respective responsibilities and are intended to provide independent 

assessments of HHS programs and operations in order to reduce waste, abuse, and 

mismanagement and to promote economy and efficiency throughout the department. 

Office of Evaluation and Inspections 

The OIG's Office of Evaluation and Inspections (OEI) conducts short-term management and 

program evaluations (called inspections) that focus on issues of concern to the department, the 

Congress, and the public. The findings and recommendations contained in the inspections 

reports generate rapid, accurate, and up-to-date information on the efficiency, vulnerability, and 

effectiveness of departmental programs. 

Office of Investigations 

The OIG's Office of Investigations (OI) conducts criminal, civil, and administrative 

investigations of allegations of wrongdoing in HHS programs or to HHS beneficiaries and of 

unjust enrichment by providers. The investigative efforts of OI lead to criminal convictions, 

administrative sanctions, or civil monetary penalties. The OI also oversees state Medicaid fraud 

control units, which investigate and prosecute fraud and patient abuse in the Medicaid program. 

Office of Counsel to the Inspector General 

The Office of Counsel to the Inspector General (OCIG) provides general legal services to OIG, 

rendering advice and opinions on HHS programs and operations and providing all legal support 

in OIG's internal operations. The OCIG imposes program exclusions and civil monetary 

penalties on health care providers and litigates those actions within the department. The OCIG 

also represents OIG in the global settlement of cases arising under the Civil False Claims Act, 

develops and monitors corporate integrity agreements, develops model compliance plans, 

renders advisory opinions on OIG sanctions to the health care community, and issues fraud 

alerts and other industry guidance. 

EXECUTIVE SUMMARY 

OBJECTIVE 

To determine if the Centers for Medicare & Medicaid Services’ (CMS) reimbursement policy 

for the provision of antigens for allergen immunotherapy accurately reflects the resources used 

in a typical physician’s practice. 

BACKGROUND 

Allergies, hypersensitive immune reactions to substances that are otherwise harmless, afflict one 

in six Americans. Substances which can trigger allergies are called antigens, and include such 

things as dust, molds, and pet dander. Symptoms range from mild irritation to life-threatening 

anaphylaxis. Medicare pays for the treatment of allergies through allergen immunotherapy, or 

allergy shots. In this therapy, a physician administers gradually increasing concentrations of an 

antigen in order to desensitize the patient. Treatment generally lasts from 3 to 5 years. 

The preparation of antigens for allergy shots, but not the injection itself, is billed under Current 

Procedural Terminology (CPT) code 95165, professional services for the provision of 

antigens for allergen immunotherapy; single or multiple antigens, per dose. Traditionally, 

a dose was defined as the amount of serum administered in each allergy shot. In 1998, the 

CMS revised the definition to be the total amount of serum delivered each treatment session, 

regardless of the number of shots. After receiving many comments from specialty 

organizations, the CMS changed the definition in the November 1, 2000 Federal Register, 

effective January 1, 2001, to “a one cc aliquot [part] from a single multidose vial.” 

We conducted a survey of a stratified random sample of 306 physicians who provide allergen 

immunotherapy. We received responses from 186 of these for a response rate of 60.8 percent. 

In addition, we conducted follow-up interviews with several sample physicians, interviewed and 

reviewed documentation from 25 of 27 Medicare carriers, and reviewed the Medicare law, 

regulation, and policy related to CPT code 95165. 

Antigen Preparation 1 OEI-09-00-00530 
FINDINGS 

Resources used in allergen immunotherapy differ from CMS assumptions 

Based on our analysis, we found that data used by CMS to calculate practice expense inputs 

for CPT code 95165 are not accurate. The CMS estimates that in a typical practice, 

physicians provide immunotherapy from 10 cc multidose vials in shots of 1 cc each. We found 

that the median vial size is 4.9 cc and the median injection volume is 0.47 cc. In addition, while 

the current calculations assume 5 antigens are in each vial of immunotherapy, we found that a 

typical vial contains approximately 8 antigens. Lastly, while the new definition of a dose 

incorporates 2.2 minutes of clinical staff time, our research indicates that each dose requires 3.0 

to 4.5 minutes to prepare. Practice expense calculations for CPT code 95165 do not factor in 

the dilution boards the typical provider creates, but the allocation per unit for this expense 

would probably be minimal. 

Almost 75 percent of providers are aware of the new definition of a dose 

Nearly three-quarters of immunotherapy providers know about the revision, mainly through 

their specialty society. However, only 44 percent of all immunotherapy providers have 

changed their billing as a result. In addition, although the revision was intended for practice 

expense calculation and billing purposes only, approximately 14 percent of immunotherapy 

providers have begun giving 1 cc injections or changed other practice patterns. Providers 

generally prefer the traditional definition of a dose as the amount of antigen given in a single 

injection over the current or an alternate definition. 

CONCLUSION 

Based on our analysis of data and information from a random sample of allergists, we conclude 

that CMS did not have accurate data when it calculated the practice expense component for 

CPT code 95615. After consulting with CMS, we conclude that CMS should use this report 

to help refine the practice expense inputs for this code as part of their normal process rather 

than making an immediate change. Since some physicians modified their practice based on the 

changes in reimbursement, CMS should emphasize that physicians need modify only their billing 

to comply with the new definition in any guidance it plans to offer in the future. We also noted 

that most physicians rely on their specialty societies, rather than CMS or its carriers, for 

information about Medicare policy changes. Therefore, to ensure physicians are getting 

accurate information, CMS and the carriers may want to work directly with the societies to 

explain any policy changes and revisions. 

Antigen Preparation 2 OEI-09-00-00530 
TABLE OF CONTENTS 

PAGE

EXECUTIVE SUMMARY ...................................................... 1

INTRODUCTION

Background ............................................................. 4

Methodology ............................................................ 7

FINDINGS 

Typical immunotherapy practices ............................................. 9

Practice expense inputs inaccurate ........................................... 11

Providers aware of revision ................................................ 13

CONCLUSION ............................................................. 16

APPENDICES

Appendix A: Glossary of Terms ............................................. 17

Appendix B: Confidence Intervals for Selected Statistics .......................... 18

Appendix C: P-values for Selected Comparisons ................................ 21

ACKNOWLEDGMENTS ..................................................... 22

Antigen Preparation 3 OEI-09-00-00530 
INTRODUCTION 

OBJECTIVE 

To determine if the Centers for Medicare & Medicaid Services’ (CMS) reimbursement policy 

for the provision of antigens for allergen immunotherapy accurately reflects the resources used 

in a typical physician’s practice. 

BACKGROUND 

Allergies and Their Treatment 

Allergies afflict one in six Americans. People with allergies experience hypersensitive immune 

system responses to substances, called allergens, which are harmless to non-allergic people. 

Common allergens include pollen, mold, and animal dander. Allergens are a type of antigen, 

which is any foreign substance which triggers an immune response, including substances which 

are universally harmful like pathogenic viruses and bacteria. Allergy symptoms range from mild 

irritation to anaphylaxis, a medical emergency involving an acute systemic allergic reaction. 

The CMS pays for allergy testing of Medicare beneficiaries and for their treatment through 

allergen immunotherapy. In this treatment, more commonly known as allergy shots, a physician 

administers gradually increasing amounts of an allergen to the patient over a period of several 

weeks. Upon reaching a maintenance level, the patient continues to receive injections on a 

regular basis, generally for at least 3 to 5 years. Allergy shots are normally reserved for those 

patients experiencing intolerable symptoms that do not respond to other therapies. 

Allergists and immunologists, who specialize in the diagnosis and treatment of allergies, provide 

the bulk of allergen immunotherapy services for Medicare beneficiaries. In addition, many 

otolaryngologists (commonly known as ear, nose, and throat doctors, or ENTs) treat allergies, 

especially those affecting the respiratory system. General internists, family practitioners, and 

other physicians also provide some immunotherapy services.1 

The practice of immunotherapy varies among providers. In one common mode, a physician 

creates a “treatment set” by first creating a vial containing the specific antigen mix for a given 

patient. From that vial, the physician then makes multiple diluted vials to 

1

In this report, we will refer to allergists and immunologists as “general allergists” and otolaryngic allergists 

as “otolaryngic allergists” or “ENT allergists.” 

Antigen Preparation 4 OEI-09-00-00530 
provide lower concentration mixes that will be needed to “step up” the patient to the 

maintenance level. 

Alternatively, a provider may create a treatment or dilution 

board as a first step in administering allergy shots (see 

Figure 1). As with treatment sets, boards contain multiple 

dilutions of antigens. Rather than dilutions specific to each 

patient, however, the provider creates diluted vials of each 

antigen serum used in his or her practice. The doctor may 

then draw particular antigens from the board and mix them 

in a multidose vial to be used for a given patient over 

multiple treatment sessions; alternatively, the doctor may 

then treat “off the board,” meaning he or she mixes and 

Figure 1: Dilution Board 

delivers each injection individually and directly from the board. 

Instead of using his or her own treatment sets or boards, a provider may choose to order 

treatment vials for each patient from a supplier, and perform only injection and observation 

services. No matter what practice is employed, antigen mixes have a finite “shelf life,” which is 

inversely proportional to their strength, and must be discarded if not used within a certain time. 

Payment for Physician Services 

Since 1992, Medicare has paid for physician services under a national fee schedule. Under this 

strategy, each medical procedure is assigned a relative value which measures the cost to 

perform the service compared to the cost to perform other covered services. Three factors 

determine the relative value of a service: physician work, practice expense, and malpractice 

expense. The physician work component, which is a measurement of the time, intensity of 

effort, and skill required for a service, constitutes 55 percent of the total value. Practice 

expense, which is 42 percent of the total, estimates the costs of doing business for a physician, 

including such expenses as staff salaries, overhead, and supplies. Malpractice expense, i.e., the 

cost of physician liability insurance, represents the remaining 3 percent. Payment for a given 

service is a function of its relative value and a geographic index based on the location where the 

service was provided. 

The American Medical Association’s Relative Value Update Committee was formed in 1991 to 

provide input on relative value units. In addition to recommending work inputs, the Committee 

comments on CMS’ proposed interim relative value units. The Committee is comprised of 29 

members, most of whom represent major specialty societies, including otolaryngology, but not 

allergy/immunology. An advisory commission embodying each of the 98 specialties in the 

Association’s House of Delegates provides support for the Committee. 

Antigen Preparation 5 OEI-09-00-00530 
The Association plays another important role in fee schedule payments by appointing the panel 

that maintains the list of Current Procedural Terminology (CPT) codes which are used by 

providers to bill Medicare. The CMS adopted CPT codes in 1983 as part of its Common 

Procedure Coding System. More 

than 7,000 codes appear in the current 

edition of the CPT manual. 

CPT Code 95165 

Medicare allowed approximately 

$98 million in charges for allergen 

immunotherapy codes in 2000. 

Nearly half of these charges, 

$47 million, were for CPT code 

95165, professional services for the 

provision of antigens for allergen 

immunotherapy; single or multiple 

antigens, per dose. This code 

describes the preparation of antigen 

Table 1: Median 95165 billing by specialty 

Specialty Year Allowed 

amount Units 

Per unit 

allowed 

amount 

General 

allergists 

2000 $20.00 2.00 $8.35 

2001 $24.90 3.00 $9.00 

ENT 

allergists 

2000 $70.00 10.0 $8.14 

2001 $80.00 10.0 $8.65 

Other 

physicians 

2000 $22.36 2.00 $8.36 

2001 $21.90 2.00 $8.82 

Figure 2: 

Vial and 

10 cc Syringe 

serums for use in immunotherapy, but not their injection. General allergists submitted about 

two-thirds of the claims for CPT code 95165, and ENT allergists account for about 20 

percent. Most of the remainder come from internists, general practitioners, family doctors, and 

various group practices. Although per unit allowed charges are fairly constant across different 

specialties, ENT allergists bill more units (and receive greater reimbursement) per claim than 

other specialties (see Table 1). 

The interpretation of CPT code 95165 has been controversial. The code is unlike others in that 

it includes the concept of a ‘dose,’ which is not defined in the CPT manual. Traditionally, 

providers and payers defined a dose as the amount of antigen given in a single injection. In May 

1998, CMS updated the carrier manual to define a dose as “the total amount of antigen to be 

administered to a patient during one treatment session, whether mixed or in separate vials.” 

Private payers, however, did not adopt this change; as a result, they paid 590 percent more per 

unit of CPT code 95165 than Medicare in 1999.2 After this change was instituted, the Relative 

Value Scale Update Committee recommended that CMS return to the traditional definition for 

the 1999 fee schedule update. At the time, though, CMS did not feel a revision was 

appropriate because the Committee failed to comment on the direct practice expense inputs to 

the code. In November 2000, after receiving many comments from specialty organizations, 

CMS revised the inputs for CPT code 95165. In this revision, effective January 1, 2001, 

CMS defines a dose, for billing and practice expense calculations, as “a one cc aliquot [part] 

2

In fact, according to OIG analysis, private payers pay significantly more for nine allergen immunotherapy 

codes than Medicare, and significantly less for the CPT injection codes 95115 and 95117. 

Antigen Preparation 6 OEI-09-00-00530 
from a single multidose vial.”3 All practice expense inputs for CPT code 95165 are based on 

this definition, although no allocation is made for resources and work used to create treatment 

or dilution boards. 

METHODOLOGY 

Survey 

We used a mail survey as the primary tool to accomplish the purpose of this study. The survey 

solicited mainly factual information on physicians’ practice patterns, including the time and 

resources used in preparing and administering allergy shots. We conducted extensive pretesting of the survey instrument to ensure that we were using accurate and understandable 

terminology and to improve the clarity and logical flow of the questions. 

We used a stratified random sample to select physicians to whom we sent the survey. From 

2001 National Claims History (NCH) data, we defined our universe as physicians appearing on 

claims for CPT code 95165 allowed in an office setting. These physicians were divided into 

three strata: allergists and immunologists in the first stratum, otolaryngologists in the second, 

and general practitioners, family doctors, internists, and group practices and clinics in the third. 

Together, these three strata accounted for 95 percent of the claims submitted for CPT code 

95165 in 2001. 

We randomly selected 102 physicians from each stratum to participate in the survey. To obtain 

names and addresses for these physician, we ran a match against CMS’ unique provider 

identification number, or UPIN, master file and did our own internet research, which resulted in 

301 valid names and addresses. We sent surveys to each of these addresses and received 

Table 2: Sample and response rate 

Stratum Physicians 

in universe 

Physicians 

in sample 

# of surveys 

mailed 

# of 

responses 

# usable 

1 (Allergists) 2348 102 101 69 69 

2 (ENTs) 1974 102 101 65 61 

3 (Others) 1229 102 99 52 47 

Total 5551 306 301 186 177 

responses from 186 (60.8 percent). Nine of these responses, 

3

Medicare does not accept separate CPT codes for physicians who treat off the board. These physicians 

submit claims based on the same 1 cc standard. 

Antigen Preparation 7 OEI-09-00-00530 
however, did not contain usable information. Responses were weighted according to each 

stratum’s representation in the population. Our sample design and response rate were adequate 

to make projections to the universe with a reasonable degree of precision. Table 2 (previous 

page) shows selected information for the three strata. 

Responses to each survey question varied greatly; for instance, respondents reported using 

from 1 to 38 antigens in a multidose vial and injecting from .05 cc to 4.0 cc of serum in each 

allergy shot. Given this variation, we used the median as representative of a ‘typical’ practice, 

since it is less affected by extreme values than the arithmetic mean. We received a large number 

of zero responses concerning questions about the amount of clinical staff time spent creating 

boards and vials and about the number of boards prepared in a year. For these questions, the 

median may not be an appropriate representation of a typical practice, so we include the mean 

as well. In all such cases, however, we were able to make comparisons among subgroups only 

with mean values. 

Non-respondent analysis. We used chi-square tests and linear regression to compare nonrespondents to respondents in terms of their stratum, year 2001 claims volume (of CPT code 

95165), Medicare patient volume, mean number of services per claim, mean number of 

services per patient, and population and urban/rural characteristics of the county in which they 

practice. None of these tests was significant at the 95 percent confidence level. 

Other Data 

We interviewed 25 of the 27 Medicare carriers about guidance they received from CMS and 

any instructions they issued to their physician communities. We asked for copies of any written 

guidance distributed to providers, which we evaluated for completeness and clarity. Two 

carriers did not respond to numerous interview requests. 

In addition, we spoke to several representatives of national allergy associations and consulted 

with practicing physicians. Several local allergists allowed us to observe the preparation of 

antigens and helped us develop our survey instrument. Lastly, we reviewed laws, regulations, 

policy letters, and other materials related to CPT code 95165. 

This study was conducted in accordance with the Quality Standards for Inspections issued by 

the President’s Council on Integrity and Efficiency. 

Antigen Preparation 8 OEI-09-00-00530 
FINDINGS 

We primarily used a national survey of a random sample of practitioners of allergen 

immunotherapy to develop the findings of this report. In addition to the survey, we interviewed 

staff and evaluated guidance documents from Medicare carriers. Lastly, we reviewed policy 

and regulations concerning CPT code 95165 and spoke with allergen immunotherapy 

providers. Based on our analysis, we found that current practice expense calculations do not 

accurately reflect typical practices among immunotherapy providers. Also, while most 

providers are aware of the new definition of a dose for CPT code 95165, most say it does not 

correspond with the way they provide allergen immunotherapy. 

Physicians typically use dilution boards to prepare multidose 

vials 

Most physicians create several boards per year 

More than 75 percent of providers indicate that they create boards either for directly treating 

patients or as a first step in creating multidose vials. Nearly all ENT allergists use boards in 

some fashion, compared to 63 percent of general allergists and 69 percent of other physicians. 

Regardless of specialty or mode of practice, 

the typical provider prepares 3.6 (median; 

mean=7.6) boards per year. Physicians in 

counties located entirely in metropolitan areas 

tend to prepare boards more often than their 

less urban counterparts, as do physicians who 

at least sometimes treat off the board. In 

addition, physicians who provide allergen 

immunotherapy, but do not identify themselves 

as allergists, produce fewer boards than ENT 

or general allergists.4 

Physicians and their staff spend about 

46 minutes (median; mean=93 minutes) 

creating each board. The greatest amount of 

time is attributed to registered nurses, though 

physicians, licensed vocational 

Figure 3: More ENT allergists create boards 

4

We found no evidence of a relationship at the 95 percent confidence level between the number of boards 

prepared and the number of the physician's patients on allergen immunotherapy. 

Antigen Preparation 9 OEI-09-00-00530 
5

A single physician rarely uses all of these types of staff, but each type is used by at least one physician in

the sample.

6

This effect is independent of the specialty of the physician.

Antigen Preparation 10 OEI-09-00-00530

Figure 4: 

nurses, medical assistants, and other staff, such as allergy technicians, sometimes contribute.5

Otolaryngic allergists spend significantly more time (167 minutes) preparing each board than do

general allergists (66 minutes) or other specialties (63 minutes). 

however, that the amount of staff time needed is associated with treating off the board. 

addition, physicians who submitted a greater number of claims of CPT code 95165 tend to

take more time preparing boards. 

more antigens or larger volumes of antigen on each board.6

 Fewer than 20 percent of providers treat off the board

Most physicians prepare multidose vials of

allergen immunotherapy from a treatment or

dilution board rather treat off the board. 

About 81 percent of physicians provide

immunotherapy exclusively from multidose

vials. 

of treating off the board and vials, while only

5 percent treat exclusively off the board. 

Treating off the board is much less common

among ENT allergists (5.45 percent) than

either general allergists (26.6 percent) or

other specialties 

(24.8 percent).

Administering shots directly off the board is a

practice quite different from first creating

multidose vials for each patient. 

treating off the board is an important factor in the outcomes of several other survey questions. 

Time spent preparing vials, the number of injections given per treatment session, and a

provider’s response to the January 2001 change all are influenced by this practice. 

these effects will be discussed later in this report.

Fewer ENT allergists treat off the board

We found no evidence,

In

This seems logical in that high-volume practices may require

Another 14 percent use a combination

As such,

Each of
More than three-fourths of physicians purchase their allergen immunotherapy 

supplies individually 

An overwhelming proportion (85.5 percent) of practitioners purchase immunotherapy supplies 

individually. Even in group and clinic settings, more than three-quarters of physicians purchase 

their supplies independently. Physicians who submit a relatively large number of claims for CPT 

code 95615 (more than 50 in the first 6 months of 2001) are more likely to buy supplies on 

their own. Only one respondent to the survey had a purchasing arrangement with other 

physicians outside his or her group. 

We followed up with nine physicians to determine why they did not enter into group purchasing 

arrangements. Almost all identified the lack of standardized antigen serum across suppliers as a 

primary reason for maintaining individual arrangements. They explained that serums differ 

across manufacturers and techniques for mixing antigens and diluent are directly related to type 

of serum obtained from a specific supplier. Therefore, it would be difficult to get each physician 

in a group purchasing arrangement to agree to the same supplier. According to our 

interviewees, since most physicians are able to negotiate some discounts on allergen 

immunotherapy supplies purchased individually, the difficulty in designing a group arrangement 

would likely outweigh any potential cost savings. In fact, nearly half of those interviewed had 

considered group arrangements at some point, but had ultimately decided against them. 

Resources used in allergen immunotherapy differ from CMS 

assumptions 

The one cc aliquot accepted by

CMS as a typical injection of Table 3: Resources used in a typical practice differ from assumptions

CPT code 95165 is much too 

large, according to our survey. 

We found that the median 

volume of an injection is 

about 0.47 cc, less than half the 

figure in the Federal Register 

(FR).7 About 48 percent of 

physicians typically give 

injections of .5 cc, and another

31 percent inject even smaller

amounts. The specialty of the physician has a strong relationship with the size of injection they

Resource CMS Estimate Survey Estimate 

Staff time 2.2 minutes 3.0 minutes 

Vial size 10 cc 4.90 cc 

Number of antigens in 

vial 

5 7.95 

Antigen volume as 

percentage of total 

100% 59% 

Volume of injection 1.0 cc 0.47 cc 

7

65 FR 65393, November 1, 2000. 

Antigen Preparation 11 OEI-09-00-00530 
Antigen Preparation 12 OEI-09-00-00530

Figure 5: administer; 91 percent of ENT

allergists give injections of .5 cc or less,

compared to about 72 percent of other

physicians. 

all specialties give 1.6 injections per

treatment session. 

off the board tend to give more

injections, an average of 2.1 compared

to 1.5 for those who do not.

The January 2001 definition of a dose

assumes physicians typically draw

doses from a 10 cc multidose vial. 

found that about 51 percent of

physicians use a 5 cc multidose vial in

their practice while only 31 percent use

a 10 cc vial. 

of physicians are almost evenly divided between those that use vials of less than 5 cc capacity

and those that use vials of greater than 5 cc, but less than 10 cc. 

use vials even larger than 10 cc. 

specialty of the provider, as shown in Figure 5. Without regard to specialty, the median

capacity of a vial is 4.90 cc.

The Federal Register publication assumes that 5 antigens are present in a typical multidose

vial, without any diluent. 

approximately 8 antigens. 

average, compared to about 7.8 for solo practitioners or physicians in a single-specialty group. 

In addition, our survey indicates that a typical multidose vial contains only about 59 percent

antigen by volume; the rest is diluent.

According to our respondents, the current rule does not sufficiently account for the time needed

to create multidose vials. 

time as a practice expense. 

requires closer to 3.0 (median) to 4.5 (mean) minutes of staff time per dose. 

to physicians’ offices, however, suggest that this figure may be inflated; additional direct

observation would be needed to confidently report the amount of time required. 

boards, our respondents attribute the greatest portion of time spent creating vials to registered

nurses. 

dedicate less staff time (2.9 minutes per dose) to creating a vial than those that exclusively use

vials (4.8 minutes per dose).

Vial size varies by specialty

On average, physicians of

Physicians who treat

We

The remaining 18 percent

A few respondents said they

The size of vial that is used is strongly correlated with the

According to our survey, a typical multidose vial contains

Providers in a clinic setting use more antigens than others: 11.7 on

The new definition of a dose incorporates 2.2 minutes of clinical staff

Our survey data suggests that preparing antigens in a multidose vial

Our limited visits

As with

Physicians who sometimes treat off the board in addition to using multidose vials
Almost 75 percent of providers are aware of the new 

definition of a dose 

Providers primarily rely on their specialty society or association for information 

Nearly three-quarters of physicians who provide allergen immunotherapy are aware of the

January 2001 revision. A positive relationship exists between the number of patients for whom

the physician provides immunotherapy and their probability of being aware of the revision. 

Also, general allergists are more likely to know of the revision than ENT allergists, who, in turn,

are more likely than other providers to be aware of the change.

Specialty societies are important sources of information for providers. Fifty-nine percent of

physicians first learned of the change from their society. In contrast, only 29 percent first

learned of the change from their Medicare carrier. Non-allergists make up a large part of this

group, reflecting their low rate of membership in allergy-related specialty societies.

Although relatively few physicians learned of the revision from their carrier, the

25 carriers we contacted all had received guidance from CMS on the new rule and had issued

a provider bulletin explaining the change. Approximately half of the carriers we interviewed

sent a newsletter to their physicians outlining the change and posted notices on their physician

web site; the remainder only mailed a newsletter or bulletin. The majority of carriers (22 of 25)

issued these instructions between November 2000 and January 2001, though one carrier did

not issue formal instructions until June 2001.

Most of the guidance issued by carriers reiterated the CMS guidance almost verbatim. We

found most of the written notices to be clear and easy to understand, although four notices

failed to adequately highlight information regarding CPT code 95165. We found that one

notice was particularly confusing because it combined information for CPT code 95165 with

information for CPT code 95115. On the other hand, one carrier offered several clinical

examples in its bulletin to help clarify the new rule.

Antigen Preparation 13 OEI-09-00-00530 
Figure 6: 

The revised definition has led some physicians to change billing and medical 

practices 

Most physicians did not change their billing 

or medical practice because of the new 

definition. 

57 percent of physicians were either 

unaware of the revision or did not make any 

changes in response to it. 

latter group explained that they had already 

been billing Medicare according to the 

January 2001 definition before it went into 

effect. 

Fifty-four percent of physicians who were 

aware of the new definition changed their 

billing as a result. 

these physicians say they now bill 1 cc as a 

dose, as outlined in the Federal Register. 

Another 16 percent report that they no longer bill for dilutions. 

specify the particular change or indicated a change other than the two listed above. 

Some experts expressed concern that the revision as published in the Federal Register would 

cause physicians to alter their medical practice as well as their billing. 

somewhat by our data: 

say they have changed how they administer allergen immunotherapy in response. 

explained that they now administered 1 cc as a dose for each Medicare patient, while others 

altered other aspects of their practices. 

practice of medicine and, in fact, issued an update to the carrier manual in September 2001 to 

clarify this point. 

Only 11 percent of practitioners prefer the new definition of a dose 

According to our survey, more practitioners (46.7 percent) prefer the traditional definition of a 

dose, the amount of antigen administered in a single injection, than any other. 

percent feel that the definition should be based on a particular volume of antigen, as it is 

currently. 

the 1998 guidance of the total amount of antigen administered in an office visit. 

Many respondents, as well as physicians to whom we spoke in preinspection, offered specific 

recommendations for an improved definition. 

both the past and current definitions is they do not account for time and 

Physicians' response to revision 

Approximately 

Several of the 

About one-quarter of 

The remainder either did not 

This concern is borne out 

almost 20 percent of physicians who were aware of the new definition 

Some of these 

The CMS, however, did not intend to dictate the 

Only about 11 

Seventeen percent of practitioners said that the definition of a dose should revert to 

Several believe one of the main problems with 

Antigen Preparation 14 OEI-09-00-00530 
resources used to create treatment and dilution boards. Others suggest that the definition lacks 

consideration for the different strength dilutions used in creating vials. Still others say that it is 

more appropriate to base the definition on the number and strengths of allergenic extracts used 

rather than a volume of serum, which could contain any number of allergens. Several providers 

expressed sympathy for CMS’ dilemma in defining a dose amid a wide variety of practices. 

Antigen Preparation 15 OEI-09-00-00530 
CONCLUSION 

The CMS commented on the working draft of this report and concurred with our findings. They 

indicated, however, that CMS will take no action at this time to address CPT code 95165. The 

CMS believes that using a 10 cc vial and 1 cc aliquots as the basis for practice expense 

calculations are not significantly different from using a 5 cc vial and 0.5 cc aliquots. Also, 

according to CMS, allocating the time and resources spent creating a dilution board to each 

individual dose would result in a minuscule, if any, change in payment. The clinical staff time 

required per dose, as stated in the report, requires more study before it could be used as a basis 

for changing reimbursement. The amount of antigen in a vial, however, is a practice expense 

issue that CMS has indicated they may address in the future. 

With CMS’ comments in mind, we conclude that although the agency did not have accurate data 

when it calculated the practice expense component for CPT code 95615, there is no compelling 

need for immediate change. Therefore, CMS could use the information in this report to help 

refine the practice expense inputs for CPT code 95165 as they see fit, perhaps in conjunction 

with the next meeting of the Practice Expense Advisory Committee. Since some physicians 

modified their practice based on the changes in reimbursement, CMS could continue to 

emphasize that physicians need modify only their billing to comply with the new definition in any 

guidance it plans to offer in the future. We also noted that most physicians rely on their specialty 

societies, rather than CMS or its carriers, for information about Medicare policy changes. 

Therefore, to ensure physicians are getting accurate information, CMS and the carriers may 

want to work directly with the societies to explain any policy changes and revisions. 

Antigen Preparation 16 OEI-09-00-00530 
APPENDIX A 

Glossary of Terms 

Aliquot - A part of a whole which is a proper divisor of that whole [Webster’s]; used in the Federal 

Register definition of a dose to mean an extract from a multidose vial. 

Allergy - Reactions of the immune system to substances that, in most people, cause no symptoms. 

[AAAAI website] 

Allergen - A foreign substance that leads to allergies by starting an immune response. [AAAAI 

wesbite] 

Anaphylaxis - A medical emergency which involves an acute systemic allergic reaction. [AAAAI 

website] 

Antigen - A substance that can trigger an immune response. [AAAAI website] 

Diluent - A liquid used to dilute the strength of an antigen serum. 

Immunotherapy - (“allergy shots”) A form of preventive and anti-inflammatory treatment of allergy. 

Immunotherapy involved gradually increasing doses of allergen(s), causing a decrease in immune 

sensitivity to the allergen. [AAAAI website] 

Maintenance level - The maximum antigen concentration and volume tolerated by a patient and at 

which they will be given immunotherapy over a period of time. 

Multidose vial - A vial containing antigen serum intended to be used for multiple injections of a 

particular patient. 

Treatment or dilution board - A board used to store multiple vials of antigen serums at various 

concentrations, for use either in directly treating patients or in creating multidose treatment vials which 

are then used to treat patients. 

Treat off the board - Mix and inject shots directly from a treatment board rather than first creating 

multidose vials. 

Treatment set - A set of multidose vials, prepared for a single patient, which is made up of vials at 

various concentrations and used to “step up” the patient to a maintenance level. 

Antigen Preparation 17 OEI-09-00-00530 
APPENDIX B 

Confidence Intervals for Selected Statistics

The following table shows the point estimates and 95 percent confidence intervals for selected 

statistics, in the order they appear in the findings. In addition, the table shows point estimates 

and confidence intervals for both the median and mean, where applicable. These calculations are 

weighted according to the stratification described in the methodology. 

Statistic N Point 

Estimate 

95 Percent 

Confidence Interval 

FINDING I 

Percent of physicians who use boards 177 75.37% 69.24% - 81.49% 

Mean number of boards prepared per year 146 7.56 4.46 - 10.66 

Median number of boards prepared per year 146 3.57 2.87 - 3.73 

Mean time (minutes) spent preparing each 

board 

154 92.50 75.34 - 109.67 

Median time (minutes) spent preparing each 

board 

154 45.71 28.37 - 67.49 

Percent of physicians who treat exclusively using 

multidose vials 

166 80.66% 74.81% - 86.50% 

Percent of physicians who mix using vials and 

boards 

166 14.12% 8.98% - 19.26% 

Percent of physicians who treat exclusively off 

the board 

166 5.22% 1.87% - 8.58% 

Percent of physicians who purchase supplies 

independently 

176 85.53% 80.57% - 90.48% 

Percent of physicians in group/clinic settings 

who purchase supplies independently 

91 78.16% 69.79% - 86.53% 

FINDING II 

Mean volume (cc) of injection 172 .578 .505 - .651 

Antigen Preparation 18 OEI-09-00-00530 
APPENDIX B 

Median volume (cc) of injection 172 .470 .463 - .477 

Percent of physicians who inject .5 cc 172 47.57% 40.18% - 54.96% 

Percent of physicians who inject < .5 cc 172 30.80% 23.93% - 37.66% 

Mean number of injections per session 172 2.36 1.99 - 2.73 

Median number of injections per session 172 1.59 1.50 - 1.69 

Percent of physicians who use a 5 cc vial 155 50.84% 43.22% - 58.47% 

Percent of physicians who use a 10 cc vial 155 31.13% 24.09% - 38.18% 

Percent of physicians who use a <5 cc vial 155 9.54% 4.85% - 14.24% 

Percent of physicians who use between a 5 and 

10 cc vial 

155 7.03% 3.14% - 10.92% 

Percent of physicians who use a >10 cc vial 155 1.45% <= 3.07% 

Mean vial capacity (cc) 155 6.91 6.33 - 7.49 

Median vial capacity (cc) 155 4.90 4.83 - 4.97 

Mean number of antigens per vial 155 9.84 8.84 - 10.83 

Median number of antigens per vial 155 7.95 7.61 - 9.91 

Antigen as a proportion of vial volume 151 58.9% 55.55% - 61.78% 

Mean time (minutes) to create a dose 147 4.45 3.69 - 5.22 

Median time (minutes) to create a dose 147 2.98 2.91 - 4.05 

FINDING III 

Percent of physicians aware of revision 177 73.84% 67.81% - 79.88% 

Percent of physicians who learned of revision 

from their specialty society 

122 58.93% 50.50% - 67.35% 

Percent of physicians who learned of revision 

from their carrier 

122 29.03% 21.26% - 36.80% 

Percent of physicians who were unaware of 

revision or did nothing in response 

177 56.53% 49.33% - 63.72% 

Antigen Preparation 19 OEI-09-00-00530 
APPENDIX B 

Percent of physicians who were unaware of 

revision 

177 26.16% 20.12% - 32.19% 

Percent of physicians who did nothing in 

response 

177 30.37% 23.53% - 37.21% 

Percent of physicians who changed practice 177 14.12% 8.87% - 19.37% 

Percent of physicians who changed billing 177 39.52% 32.39% - 46.65% 

Percent of aware physicians who changed 

billing 

122 54.21% 45.45% - 62.97% 

– percent of above who now bill 1 cc as dose 71 23.39% 13.46% - 33.32% 

– percent of above who no longer bill dilutions 71 16.26% 7.37% - 25.09% 

– percent of above who made some other 

change 

71 63.63% 52.48% - 74.78% 

Percent of aware physicians who changed 

practice 

122 19.37% 12.33% - 26.41% 

Percent of physicians who prefer traditional 

definition 

173 46.75% 39.40% - 54.09% 

Percent of physicians who prefer volume-based 

definition 

173 11.15% 6.41% - 15.90% 

Percent of physicians who prefer 1998 definition 173 17.31% 11.59% - 23.03% 

Antigen Preparation 20 OEI-09-00-00530 
APPENDIX C

Antigen Preparation 21 OEI-09-00-00530

Comparison Group Statistic Threshold Result

Mean number of

boards by

urban/rural

character of county

Rural counties 2.93 n/a

significant

Urban counties 8.82

Mean number of

boards by specialty,

pairwise

(1) General allergists 9.51 0.0167 vs.(3) - significant

(2) ENT allergists 6.96 vs.(3) - significant

(3) Non-allergists 2.43 -

Median number of

injections by

treating off the

board

Not off the board 1.51 n/a

significant

Off the board 2.06

Number of antigens

by type of practice

(1) Solo practitioner 7.81 0.00833 vs.(3) - significant

(2) Group practice 7.80 vs.(3) - significant

(3) Clinic 11.74 -

Specialty Number of respondents

Not off the board Off the board

General Allergist 60 (weighted=1278.77) 23 (weighted=463.63)

ENT Allergist 52 (weighted=1006.35) 3 (weighted=58.06)

Non-allergist 20 (weighted=292.14) 8 (weighted=96.39)

P-values for Selected Comparisons

The following table 1 shows the results t-tests for selected comparisons. 

pairwise tests of multiple groups, the particular groups tested are displayed, as is the threshold

for determining significance (calculated using the Bonferroni method.) "=0.05 for all

tests.

The next table shows a sample chi-square for the comparison between physicians specialty and

treating off the board.

 Chi-square for treating off the board by specialty = 0.0004895 - significant

Where we conducted

We used 
ACKNOWLEDGMENTS 

This report was prepared under the direction of Paul A. Gottlober, Regional Inspector General for 

Evaluation and Inspections in the San Francisco Regional Office. Other principal Office of Evaluation 

and Inspections staff who contributed include: 

Scott Hutchison, Project Leader 

Pamela Minniear, Program Analyst 

Camille Harper, Program Analyst 

Thomas Purvis, Program Analyst 

Chris Tarbell, Program Analyst 

Stephanie Lattin Program Specialist 

This inspection team would like to thank all the respondents to the survey. We would like to particularly 

thank the physicians who assisted us in designing the survey instruments and reviewing the background 

section of the report. 

For information or copies of this report, please contact the Office of Inspector General’s Public Affairs 

office at (202) 619-1343.