MEDICARE

Nurse Anesthetists 

Billed for Few Chronic 

Pain Procedures; 

Implementation of 

CMS Payment Policy 

Inconsistent

Report to Congressional Requesters

February 2014

GAO-14-153

United States Government Accountability Office
United States Government Accountability Office

Highlights of GAO-14-153, a report to 

congressional requesters

February 2014

MEDICARE

Nurse Anesthetists Billed for Few Chronic Pain 

Procedures; Implementation of CMS Payment Policy 

Inconsistent

Why GAO Did This Study

Chronic pain costs the nation about 

$600 billion each year, a quarter of 

which is borne by Medicare. One MAC, 

Noridian Healthcare Solutions 

(Noridian), began denying CRNA 

claims for certain chronic pain services 

in 2011, citing patient safety concerns. 

CMS issued a rule, effective January 

2013, clarifying that CRNAs can bill 

Medicare for “any services that a 

[CRNA] is legally authorized to perform 

in the state in which the services are 

furnished,” including chronic pain 

management services. GAO was 

asked to review Medicare’s payment 

policy regarding the provision of 

chronic pain management services by 

CRNAs. This report examines, among 

other things, (1) trends in Medicare 

provider billing for selected chronic 

pain procedures; (2) in which states 

MACs allowed payment for selected 

procedures billed by CRNAs as of 

early 2013; and (3) how MACs 

implemented the payment policy. To 

do this, GAO selected seven 

categories of chronic pain procedures, 

in consultation with pain care experts. 

GAO analyzed Medicare claims data 

from 2009 through 2012, by provider 

type and geography. To determine 

which MACs allow CRNA payments 

and how MACs implemented CMS’s 

policy, GAO interviewed medical 

directors at all nine MACs.

What GAO Recommends

GAO recommends that CMS provide 

specific instructions to MACs on 

(1) how to determine coverage with 

reference to a state’s scope of practice 

laws, and (2) the application of the 

CRNA supervision rule. HHS 

concurred with these 

recommendations.

What GAO Found

From 2009 through 2012, certified registered nurse anesthetists (CRNA)—a type 

of advanced-practice nurse specializing in anesthesia care—billed Medicare feefor-service (FFS) for a minimal share of selected chronic pain procedures, less 

than 1⁄2 of 1 percent of these procedures in each year. Physicians without board 

certification in pain medicine billed for the majority of selected procedures each 

year, while pain physicians consistently billed for roughly 40 percent of selected 

procedures. Furthermore, although the number of chronic pain procedures billed 

by all rural providers increased from 2009 through 2012, the number of 

procedures billed by rural CRNAs declined over the period. Of all CRNA claims 

for selected procedures, the share billed by CRNAs in rural areas fell from 

66 percent in 2009 to 39 percent in 2012.

Share of Selected Chronic Pain Procedures Billed in Medicare Fee-for-Service (FFS), by 

Provider Type, 2009 and 2012

Share of procedures (in percent)

Providera 2009 2012

Certified registered nurse anesthetist 0.4% 0.3%

Nurse practitioner or physician assistant 1.0 2.3

Board certified pain physician 40.7 42.5

Other physician 57.9 54.8

Source: GAO analysis of Centers for Medicare & Medicaid Services (CMS) data.

Notes: Percentages may not add to 100 due to rounding.

a

Provider type is based largely on the specialty indicated on the claim. Where services are billed 

“incident to,” our analysis is based on the billing professional’s specialty.

As of early 2013, Medicare Administrative Contractors (MAC)—entities that pay 

medical claims on behalf of Medicare—allowed payment to CRNAs for all 

selected procedures in 19 states, allowed payment for a subset of selected 

procedures in 30 states and the District of Columbia, and denied payments for all 

selected procedures in 1 state. Where MACs allowed payment to CRNAs for only 

certain procedures, payment policies indicated substantial variation in the 

specific allowed procedures.

Three of the nine MACs took steps to implement a Department of Health and 

Human Services’ (HHS) Centers for Medicare & Medicaid Services (CMS) rule, 

effective January 2013, that defers to state scope of practice laws to inform 

coverage for CRNAs. CMS relies on MACs to review each state’s CRNA scope 

of practice laws. However, most MACs reported difficulty interpreting state scope 

of practice laws regarding the services that CRNAs are allowed to provide; MACs 

noted that state scope of practice laws generally lack detail on which specific 

services CRNAs can perform. In addition, two MACs assumed that Medicare’s 

rule requiring physician supervision for anesthesia services provided by CRNAs 

in hospital and ambulatory surgical center settings applied to chronic pain 

management services provided in all settings; this may have unnecessarily 

restricted the services for which CRNAs are allowed to bill in certain states.

View GAO-14-153. For more information, 

contact James Cosgrove at (202) 512-7114 or 

cosgrovej@gao.gov.
Page i GAO-14-153 Nurse Anesthetists and Medicare

Letter 1 

Background 6

CRNAs Billed for Few Selected Chronic Pain Procedures, Most of 

Which Were in Rural Areas 9

After Noridian Began Denying CRNA Claims, Changes in the 

Number of Chronic Pain Procedures Billed Varied across Three 

Selected States 16

As of Early 2013, MACs Allowed Payment to CRNAs for All or 

Some Selected Chronic Pain Procedures in All but One State 

and for E/M Services in Roughly Half of the States 19

Faced with Challenges, MACs Inconsistently Implemented CMS’s 

CRNA Payment Policy 24

Conclusion 27

Recommendations for Executive Action 27

Agency Comments and Our Evaluation 27

Appendix I Scope and Methodology 29

Appendix II Overall Trends in Billing by Selected Procedure 33

Appendix III CRNA Share of Selected Chronic Pain Procedures, by State 35

Appendix IV Comments from the Department of Health and Human Services 37

Appendix V GAO Contact and Staff Acknowledgments 40

Tables

Table 1: Description of Selected Chronic Pain Procedures 4

Table 2: Shares of Selected Chronic Pain Procedures and 

Provider Payments in Medicare Fee-for-Service (FFS), by 

Provider Type, 2009 through 2012 10

Contents
Page ii GAO-14-153 Nurse Anesthetists and Medicare

Table 3: Certified Registered Nurse Anesthetist (CRNA) Market 

Share for Selected Chronic Pain Procedures in Medicare

Fee-for-Service (FFS), 2009 through 2012 11

Table 4: Number of Procedures Billed and Average Annual 

Growth Rate for Selected Chronic Pain Procedures in 

Medicare Fee-for-Service (FFS), 2009 through 2012 33

Table 5: Payments and Growth Rates for Selected Chronic Pain 

Procedures in Medicare Fee-for-Service (FFS), 2009 

through 2012 34

Table 6: Certified Registered Nurse Anesthetist (CRNA) Market 

Share for Selected Chronic Pain Procedures in Medicare 

Fee-for-Service (FFS), by State, 2009 and 2012 35

Figures

Figure 1: Change in the Mix of Selected Chronic Pain Procedures 

Billed by Certified Registered Nurse Anesthetists (CRNA) 

in Medicare Fee-for-Service (FFS), 2009 through 2012 12

Figure 2: Number of Selected Chronic Pain Procedures Billed by 

All Providers and by Certified Registered Nurse 

Anesthetists (CRNA) in Urban and in Rural Areas in 

Medicare Fee-for-Service (FFS) from 2009 through 2012 14

Figure 3: Shares of Selected Chronic Pain Procedures in 

Medicare Fee-for-Service (FFS) Furnished in Rural 

Areas, by Provider Type, 2009 through 2012 15

Figure 4: Number of Selected Chronic Pain Procedures Billed to 

Medicare Fee-for-Service (FFS) in Montana, South 

Dakota, and Wyoming, 2009 through 2012 17

Figure 5: Number of Selected Chronic Pain Procedures Billed to 

Medicare Fee-for-Service (FFS) by Rural Providers in 

Montana, South Dakota, and Wyoming, 2009 through 

2012 18

Figure 6: Medicare Fee-for-Service (FFS) Payment Policies for 

Selected Certified Registered Nurse Anesthetist (CRNA)-

Provided Chronic Pain Procedures, by State, April 2013 20

Figure 7: Medicare Fee-for-Service (FFS) Payment Policies for 

Selected Certified Registered Nurse Anesthetist (CRNA)-

Provided Chronic Pain Procedures in Florida, Nevada, 

and Pennsylvania, April 2013 21
Page iii GAO-14-153 Nurse Anesthetists and Medicare

Figure 8: Medicare Fee-for-Service (FFS) Payment Policies for 

Certified Registered Nurse Anesthetist (CRNA)-Provided 

Evaluation and Management (E/M) Services, by State, 

April 2013 23

Abbreviations

AANA American Association of Nurse Anesthetists

ABMS American Board of Medical Specialties

ASA American Society of Anesthesiologists

ASC ambulatory surgical center

ASIPP American Society of Interventional Pain Physicians

CMS Centers for Medicare & Medicaid Services

CPT current procedural terminology

CRNA certified registered nurse anesthetist

E/M evaluation and management

FFS fee-for-service 

HHS Department of Health and Human Services

IOM Institute of Medicine

LCD local coverage determination

MAC Medicare Administrative Contractor

NCD national coverage determination

Noridian Noridian Healthcare Solutions

NP nurse practitioner

NPPES National Plan and Provider Enumeration System

PA physician assistant

This is a work of the U.S. government and is not subject to copyright protection in the 

United States. The published product may be reproduced and distributed in its entirety 

without further permission from GAO. However, because this work may contain 

copyrighted images or other material, permission from the copyright holder may be 

necessary if you wish to reproduce this material separately.
Page 1 GAO-14-153 Nurse Anesthetists and Medicare

441 G St. N.W.

Washington, DC 20548

February 7, 2014

The Honorable Tom Coburn

Ranking Member

Committee on Homeland Security and Governmental Affairs

United States Senate

The Honorable David Vitter

United States Senate

The Honorable Ed Whitfield

House of Representatives

More than 100 million Americans suffer from chronic pain, costing the 

nation roughly $600 billion each year, a quarter of which is borne by the 

Medicare program, according to the Institute of Medicine (IOM).1 Unlike 

acute pain—which typically has a sudden onset and is expected to last a 

short time in conjunction with a specific injury or illness—chronic pain 

lasts more than several months, and may become a disease in itself. In 

general, chronic pain management may encompass one or multiple 

therapeutic approaches based on a comprehensive patient assessment 

made during an evaluation and management (E/M) visit.2 Such 

approaches may include prescription medications, such as opioids; 

physical therapy; and chronic pain procedures, such as epidural steroid 

injections or nerve blocks. Chronic pain procedures—sometimes referred 

to as interventional pain management procedures—are minimally 

invasive, but potentially risky.3

 

1

Institute of Medicine, Relieving Pain in America: A Blueprint for Transforming Prevention, 

Care, Education, and Research (Washington, D.C.: 2011).

Most of them involve injections, and many 

of them occur around the spinal cord. The procedures are typically 

furnished in hospital outpatient departments, physician offices, or 

ambulatory surgical centers (ASC).

2

E/M services are provided by physicians and nonphysicians to assess patients’ health 

and manage their care.

3

IOM reported that certain interventional pain procedures may be effective for some 

patients, but that the usefulness of some interventional procedures may be “doubtful.” It 

also identified a number of shortcomings in the way chronic pain is managed, including 

insufficient provider education in chronic pain and limited access to care in rural areas.
 

Page 2 GAO-14-153 Nurse Anesthetists and Medicare

Recently, the issue of which types of health care providers—pain 

medicine subspecialists, other types of physicians, or nonphysician 

providers, such as advanced-practice nurses—should perform chronic 

pain management services has received heightened attention. Some 

certified registered nurse anesthetists (CRNA)—a type of advancedpractice nurse specializing in anesthesia care—provide chronic pain 

services, as well as other services such as those directly related to 

surgical anesthesia. The American Association of Nurse Anesthetists 

(AANA) has asserted that CRNAs have demonstrated their ability to 

safely and effectively deliver chronic pain management services, 

particularly for patients in rural areas where access to pain physicians is 

often limited. On the other hand, the American Society of Interventional 

Pain Physicians (ASIPP) and the American Society of Anesthesiologists 

(ASA) have argued that CRNAs—and to some extent other physicians 

without specialized training in pain medicine—are not qualified to 

comprehensively and independently treat chronic pain patients, and that 

concerns about access should not trump patient safety.

Under federal law, Medicare-covered services of a CRNA include 

“anesthesia services and related care.”4 Until recently, it was unclear 

whether this included chronic pain management services, allowing the 

Centers for Medicare & Medicaid Services’ (CMS) regional Medicare 

Administrative Contractors (MAC) discretion in determining CRNA 

coverage.5 In particular, one MAC—Noridian Healthcare Solutions 

(Noridian)—began denying CRNA claims for certain chronic pain 

management services in 2011, citing potential patient safety issues. To 

clarify the Medicare policy, CMS promulgated a rule that CRNAs can bill 

Medicare for “those services that a [CRNA] is legally authorized to 

perform in the state in which the services are furnished,” including chronic 

pain management services, effective January 1, 2013.6

 

4

42 U.S.C. § 1395x(bb)(1) (codifying section 1861(bb)(1) of the Social Security Act).

Contrary to the 

prior policy, which allowed for MAC discretion, this clarification explicitly 

defers to each state’s scope of practice laws to inform whether particular 

5

MACs are private contractors that assist CMS, an agency within the Department of 

Health and Human Services (HHS), in administering the Medicare program. They are 

responsible for reviewing and paying claims in accordance with Medicare policy, 

conducting provider outreach and education on correct billing practices, helping implement 

CMS-issued national coverage policy, and developing local coverage policies.

6

77 Fed. Reg. 68892, 69005-09 (Nov. 16, 2012) (codified at 42 C.F.R. § 410.69).
 

Page 3 GAO-14-153 Nurse Anesthetists and Medicare

CRNA services are covered under Medicare.7

You asked us to review Medicare’s payment policy regarding the 

provision of chronic pain management services by CRNAs. In this report, 

we (1) examine trends in Medicare provider billing for selected chronic 

pain procedures, (2) determine the extent to which billing for selected 

chronic pain procedures changed during the period of Noridian’s payment 

denials for CRNAs, (3) identify states in which MACs allowed payment for 

selected chronic pain procedures and E/M services billed by CRNAs as of 

early 2013, and (4) review how MACs implemented the payment policy 

regarding CRNAs.

Thus, CMS’s rule both sets 

a Medicare standard for the services that can be reimbursed and 

recognizes local variation in states’ scope of practice laws.

To address these issues, we selected seven categories of chronic pain 

procedures and related current procedural terminology (CPT) codes, in 

consultation with pain care experts.8 From an AANA-provided list of 

procedures billed by CRNAs, we selected procedures that were either 

reported by a MAC billing specialist as likely to be used to treat chronic 

pain (as opposed to acute pain), or commonly identified by payer 

resources as pain management services. For our claims analyses, we 

excluded other types of chronic pain management services, such as E/M 

and pharmacological services, because of the unavailability of reliable 

data. For a description of the selected procedures, see table 1.

 

7

Each state has its own scope of practice laws, which typically define a physician or 

nonphysician provider’s practice, qualifications, board representation, and fee/renewal 

schedule. 

8

CPT is a uniform coding system maintained by the American Medical Association used to 

identify and bill for medical procedures and services under public and private health 

insurance programs.
 

Page 4 GAO-14-153 Nurse Anesthetists and Medicare

Table 1: Description of Selected Chronic Pain Procedures

Chronic pain procedures Description

Autonomic nerve blocks Injections of local anesthetic agents to temporarily interrupt nerves or nerve trunks in 

order to diagnose or treat pain in the autonomic nervous system, a series of nerves that 

control several involuntary body movements.

Epidural injections Injections of steroids (anti-inflammatory agents), local anesthetic agents, or other 

medication into the epidural space of the spine to diagnose or treat pain radiating to the 

arms and legs, caused by the irritation of nerves in the spine. Radiological guidance is 

usually used to ensure correct needle placement.

Facet neurolytic destruction Destruction of the paravertebral facet joint nerve by a neurolytic agent, such as a 

chemical or an electric current. Radiological guidance is used to ensure correct needle 

placement.

Paravertebral facet joint injections Injections of steroids or local anesthetic agents into spinal joints to treat or diagnose back 

pain. Radiological guidance is usually used to ensure correct needle placement.

Somatic nerve blocks Injections of local anesthetic agents to temporarily interrupt nerves or nerve trunks in 

order to diagnose or treat pain in the somatic nervous system, which includes the nerves 

that extend to limbs.

Transforaminal epidural injections Specific type of epidural injection that allows the medication to be delivered into the 

foramen of the spine, which enables the provider to isolate the precise nerve root causing 

the pain. Radiological guidance is usually used to ensure correct needle placement.

Trigger point injections Injections of steroids or local anesthetic agents given to treat one or multiple pain points 

(myofascial trigger points) in a band of skeletal muscle.

Source: GAO summary of information from medical literature, federal reports, and other sources.

To examine provider billing for the selected procedures, we analyzed 

Medicare fee-for-service (FFS) paid claims from 2009 through 2012. In 

addition, we disaggregated the data into four provider types—pain 

medicine subspecialists (pain physicians), other physicians, CRNAs, and 

nurse practitioners (NP) or physician assistants (PA)—based largely on 

the specialty indicated on the claim. For procedures that were billed 

“incident to”—whereby, for example, a physician might bill for a 

supervised procedure furnished by a CRNA, NP, or PA—the actual 
 

Page 5 GAO-14-153 Nurse Anesthetists and Medicare

provider of the service is not indicated on the claim.9 These claims 

indicate the specialty of the billing professional. To the extent that 

providers furnished procedures in whole or in part that were billed 

“incident to” another professional, our analysis may have understated the 

role of those provider types. To identify procedures billed by pain 

physicians, we cross-referenced the names of physicians listed by the 

American Board of Medical Specialties (ABMS) as board certified in pain 

medicine, to a list of all Medicare providers, as maintained by CMS 

through the National Plan and Provider Enumeration System (NPPES).10

We took additional steps in an effort to narrow our focus to procedures 

used to treat chronic pain. CPT codes do not indicate whether a particular 

procedure is used to treat chronic or acute pain. To focus our review on 

chronic pain, we excluded claims with a modifier that suggests that the 

service was likely to be peri-operative. We also excluded procedures 

performed in the hospital inpatient setting in our trend analysis, as they 

are also more likely to be acute in nature.

We also disaggregated the data by provider location, including rural and 

urban status.

To determine the extent to which billing for the selected procedures 

changed during the period of MAC denials, we analyzed claims from 2009 

through 2012 in those states under Noridian’s jurisdiction where CRNAs 

had at least 1 percent of the chronic pain provider market in the period 

before their claims were denied. We examined trends in the billing of our 

selected chronic pain procedures by all provider types, both statewide 

and in rural areas. Appendix I contains a more complete description of 

our methodology for the Medicare claims analyses. 

 

9

Providers sometimes use modifiers to provide additional information on the claim about a 

service or procedure submitted to CMS. In 2009, the HHS Office of Inspector General 

recommended that CMS create a modifier that can be used to identify services billed 

“incident to.” CMS disagreed, citing difficulties distinguishing between services personally 

performed and those not personally performed. See HHS Office of Inspector General, 

Prevalence and Qualifications of Nonphysicians Who Performed Medicare Physician 

Services, OEI-09-06-00430 (Washington, D.C.: August 2009). In December 2013, CMS 

amended Medicare regulations to stipulate that services and supplies billed “incident to” a 

physician’s professional services can only be furnished by auxiliary personnel who 

“meet[ ] any applicable requirements to provide the services, including licensure, imposed 

by the State in which the services are being furnished.” See 78 Fed. Reg. 74230 (Dec. 10, 

2013) (to be codified at 42 C.F.R. § 410.26).

10Using this methodology, we were able to match 91 percent of the physicians listed as 

pain specialists by ABMS to the list of providers enrolled in the Medicare program.
 

Page 6 GAO-14-153 Nurse Anesthetists and Medicare

To identify states in which MACs allow payment for selected chronic pain 

procedures and E/M services billed by CRNAs, we interviewed medical 

directors at all nine Part A and Part B MACs to determine whether the 

MAC pays for all, a subset, or no chronic pain procedures and outpatient 

E/M services.11

We ensured the reliability of the Medicare claims data, ABMS pain 

physician data, and NPPES data used in this report by performing 

appropriate electronic data checks, reviewing relevant documentation, 

and interviewing officials and representatives knowledgeable about the 

data. We found the data were sufficiently reliable for the purpose of our 

analyses.

We then confirmed this information by obtaining coverage 

policies for specific CPT codes for each state under a MAC’s jurisdiction. 

To review how MACs implemented CMS’s 2013 payment policy, we 

interviewed CMS officials to learn about the development and 

implementation of the new rule, as well as medical directors from the nine 

MACs to determine each MAC’s approach to implementing this policy.

We conducted this performance audit from March 2013 through February 

2014 in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.

Various types of providers may perform chronic pain management 

procedures, and each provider type is subject to certain education, 

training, certification, and licensure requirements. The range of chronic 

pain management providers and their practice requirements include the 

following:

 

11CMS is in the process of reorganizing and consolidating its MAC jurisdictions. We spoke 

with the MACs that process claims for Medicare Part A—covering hospital and other 

inpatient stays—and Medicare Part B—covering hospital outpatient, physician, and other 

services. As of April 2013, there were 12 jurisdictions and 3 states under legacy contracts; 

9 MACs held the contracts for these jurisdictions.

Background

Types of Providers and 

Practice Requirements
 

Page 7 GAO-14-153 Nurse Anesthetists and Medicare

• Pain physicians. These physicians have completed a subspecialty 

fellowship training program in pain medicine recognized by ABMS.12

• Other physicians. Physicians—including those in specialty and 

primary care—without certification in pain medicine have 

comprehensive medical knowledge through their medical school, as 

well as residency training that can last from at least 3 to 7 years. 

Although board certification is optional, most physicians take an exam 

to become certified in a medical specialty.

Following medical school and a residency program in a primary 

specialty, pain physician candidates must complete an accredited 

1-year fellowship and pass an examination to receive board 

certification.

• CRNAs. According to the AANA, registered nurses with a Bachelor of 

Science in Nursing and at least 1 year of experience in an acute 

setting can pursue certification in nurse anesthesia. Graduates of 

accredited schools of nurse anesthesia, which provide 24 to 

36 months of training, must pass a national examination to receive 

their certification as CRNAs.

• Other nonphysician providers, such as NPs or PAs. To become NPs, 

registered nurses undertake advanced clinical training and complete a 

master’s program—lasting 11⁄2 to 3 years—or a doctoral program. PAs 

typically undertake roughly 2 years of master’s-level training. Both 

NPs and PAs must be nationally certified.

Providers must be licensed by the states in which they practice and 

adhere to state requirements. Physician and PA licensure is administered 

by state boards of medicine, while nursing licensure is administered by 

state boards of nursing. Furthermore, all providers are governed by state 

laws. For example, NPs may or may not be allowed to practice 

independently or prescribe medications depending on the state in which 

they practice, and PAs are generally allowed to prescribe medications, 

but must practice under the supervision of a physician. These laws can 

 

12The American Board of Pain Medicine also offers physicians certification in pain 

medicine. However, because it is not an ABMS member board, physicians receiving its 

certificate are not considered board certified in pain medicine, except for in California and 

Florida. In addition, the American Board of Interventional Pain Physicians offers 

physicians who are already board certified in an ABMS primary specialty the opportunity 

to become certified in interventional pain management through an examination; it is also 

not an ABMS member board.
 

Page 8 GAO-14-153 Nurse Anesthetists and Medicare

take precedence over other location- or payer-specific policies, such as 

hospital-based privileging.13

Although CMS has not issued a national coverage determination (NCD) 

for chronic pain management, some MACs have established local 

coverage determinations (LCD) for chronic pain procedures.14 Typically, 

these LCDs do not address which types of providers may bill Medicare for 

the services, but rather stipulate certain coverage or billing rules.15

CMS uses a physician fee schedule to determine the amounts paid to 

providers for each CPT code billed. Nonphysician providers of chronic 

pain procedures vary in the percentage of the physician fee schedule they 

receive. For example, while CRNAs are generally paid 100 percent of the 

amount a physician is paid for a given procedure under the physician fee 

schedule, NPs and PAs are generally paid 85 percent of the physician fee 

schedule.

For 

example, for procedures that may be given to a beneficiary in a series, an 

LCD may limit payment to no more than three procedures within a year. 

LCDs also contain instructions for providers on how to bill Medicare using 

various CPT codes and modifiers. A given procedure may have several 

CPT codes that indicate where on the body the procedure takes place or 

whether additional levels of a procedure were performed. For instance, 

paravertebral facet joint injections would be billed using one CPT code to 

indicate a cervical or thoracic location, and another CPT code to indicate 

a lumbar or sacral location—as well as “add-on” codes to specify when 

injections occurred on multiple levels of the spine.

16

 

13Privileging is the process whereby a health care facility grants health care providers 

permission to furnish specific services at their facility.

14NCDs stipulate coverage rules for the items and services that are reasonable and 

necessary for the diagnosis or treatment of an illness or injury. In the absence of an NCD, 

an item or service may be covered at a MAC’s discretion. In this case, a MAC may issue 

an LCD stipulating the coverage and coding rules that it uses to adjudicate claims for such 

items and services. Most coverage decisions consist of LCDs, while there are relatively 

few NCDs.

15CMS does not generally specify which types of physicians can bill for which procedures.

16For most physician services, the beneficiary is responsible for the deductible, if not 

already met, and a coinsurance of 20 percent of the physician fee schedule. Medicare 

pays the remaining 80 percent of the physician fee schedule. 

Medicare Coverage and 

Payment for Chronic Pain 

Procedures
 

Page 9 GAO-14-153 Nurse Anesthetists and Medicare

From 2009 through 2012, CRNAs billed Medicare FFS for a small share 

of our selected chronic pain procedures, while pain physicians and other 

physicians billed for the largest shares. Of the procedures billed by 

CRNAs, most were billed by CRNAs in rural areas until 2012.17

Overall, the various providers’ shares of chronic pain procedures billed to 

Medicare did not change much over the study period. (See table 2.) The 

share billed by NPs, PAs, and CRNAs combined grew from 1.4 to 

2.6 percent, with CRNA’s billing for less than 1⁄2 of 1 percent of all chronic 

pain procedures in each year. Pain physicians billed for over 40 percent 

of the selected procedures over the 4-year period, while other physicians 

billed for over half of the selected services each year. From 2009 through 

2012, the trends in shares of Medicare payments by provider type were 

largely parallel to the trends in their shares of procedures billed. (See 

table 2.) Combined, CRNAs, NPs and PAs, received less than 3 percent 

of all payments for these services throughout the period.

 

17For information on general billing trends by selected procedure, see app. II.

CRNAs Billed for Few 

Selected Chronic 

Pain Procedures, 

Most of Which Were 

in Rural Areas

CRNAs Billed for a 

Consistently Small Share 

of Selected Procedures, 

While Pain Physicians 

Billed for about 40 Percent 

of the Procedures Yearly
 

Page 10 GAO-14-153 Nurse Anesthetists and Medicare

Table 2: Shares of Selected Chronic Pain Procedures and Provider Payments in Medicare Fee-for-Service (FFS), by Provider 

Type, 2009 through 2012 

Numbers in percent

Share of procedures Share of payments

Provider 2009 a 2010 2011 2012 2009 2010 2011 2012

Certified registered nurse anesthetist (CRNA) 0.4% 0.4% 0.3% 0.3% 0.2% 0.3% 0.2% 0.3%

Nurse practitioner (NP) or physician assistant (PA) 1.0 1.3 1.7 2.3 0.7 0.9 1.2 1.9

Other physician 57.9 56.1 55.3 54.8 56.5 55.0 54.5 53.9

Pain physician 40.7 b 42.2 42.7 42.5 42.5 43.9 44.1 43.8

Source: GAO analysis of CMS data.

Notes: Percentages may not add to 100 due to rounding.

a

Provider type is based largely on the specialty indicated on the claim. Because services billed

“incident to” indicate the specialty of the billing professional, our analysis is based on the billing 

specialty. To the extent that CRNAs, for example, provided services in whole or in part that were 

billed “incident to” another professional, these data may understate the role of CRNAs in the provision 

of these procedures. 

b

The pattern of CRNA billing by type of chronic pain procedure shows that 

CRNAs consistently billed for less than 1 percent of the total. (See 

table 3.)

To identify procedures billed by pain physicians, we cross-referenced the names of physicians listed 

by the American Board of Medical Specialties (ABMS) as board certified in pain medicine to a list of 

all Medicare providers.

• CRNAs had their largest market share in epidural injections, where 

they accounted for 0.9 percent of providers’ billings in 2009; this share 

dropped to 0.6 percent in 2012.

• CRNAs billed for even smaller shares of facet neurolytic destruction 

injections, autonomic nerve blocks, and trigger point injections.
 

Page 11 GAO-14-153 Nurse Anesthetists and Medicare

Table 3: Certified Registered Nurse Anesthetist (CRNA) Market Share for Selected 

Chronic Pain Procedures in Medicare Fee-for-Service (FFS), 2009 through 2012

Numbers in percent 

Share billed by certified registered 

nurse anesthetists

Selected chronic pain procedures 2009 2010 2011 2012

Autonomic nerve blocks 0.05% 0.10% 0.09% 0.10%

Epidural injections 0.91 0.93 0.79 0.64

Facet neurolytic destruction 0.02 0.03 0.02 0.08

Paravertebral facet joint injections 0.21 0.15 0.16 0.42

Somatic nerve blocks 0.35 0.48 0.39 0.35

Transforaminal injections 0.15 0.18 0.14 0.13

Trigger point injections 0.07 0.11 0.09 0.11

Source: GAO analysis of CMS data.

Notes: The CRNA provider type is based on the specialty indicated on the claim. Because services 

billed “incident to” indicate the specialty of the billing professional, our analysis is based on the billing 

specialty. To the extent that CRNAs provided services in whole or in part that were billed “incident to” 

another professional, these data may understate the role of CRNAs in the provision of these 

procedures.

Over time, the mix of procedures that CRNAs billed to Medicare from 

2009 through 2012 changed somewhat. (See fig.1.)

• Epidural injections represented the largest share—roughly twothirds—of CRNA-billed procedures, but that share decreased to less 

than half over the period.

• The share of paravertebral facet joint injections doubled between 

2011 and 2012.

• Autonomic nerve blocks, facet neurolytic destruction, and trigger point 

injections billed by CRNAs held relatively small but growing shares of 

CRNA billing.
 

Page 12 GAO-14-153 Nurse Anesthetists and Medicare

Figure 1: Change in the Mix of Selected Chronic Pain Procedures Billed by Certified 

Registered Nurse Anesthetists (CRNA) in Medicare Fee-for-Service (FFS), 2009 

through 2012

Notes: The CRNA provider type is based on the specialty indicated on the claim. Because services 

billed “incident to” indicate the specialty of the billing professional, our analysis is based on the billing 

specialty. To the extent that CRNAs provided services in whole or in part that were billed “incident to” 

another professional, they are not captured in this figure.

By state, the trend among CRNAs’ billing for selected chronic pain 

procedures was largely stable over the 4-year period. (See app. III for 

state-by-state data.)

• CRNAs’ share increased by more than 1 percentage point in 2 states, 

declined by more than 1 percentage point in 6 states, and remained 

largely unchanged in 42 states and the District of Columbia.

• States that experienced the most growth in CRNA market share were 

New Hampshire and Tennessee, increasing 4.4 and 2.5 percentage 

points, respectively.
 

Page 13 GAO-14-153 Nurse Anesthetists and Medicare

• By 2012, the CRNA share of selected chronic pain procedures was 

highest in New Hampshire (5.5 percent), Iowa (4.3 percent), and 

Kansas (4.0 percent). In 43 states and the District of Columbia, the 

CRNA share remained under 1 percent.

Although the number of selected chronic pain procedures billed by all 

rural providers increased somewhat from 2009 through 2012, the number 

of procedures billed by CRNAs in rural areas declined over the period. 

(See fig. 2.) Of all CRNA claims for selected procedures, the share 

submitted by providers in rural areas fell from 66 percent in 2009 to 

39 percent in 2012; meanwhile, the share of selected procedures 

nationwide billed by all rural provider types was roughly 11 percent in 

both 2009 and in 2012.

Of All CRNA-Billed 

Chronic Pain Procedures 

from 2009 through 2011, 

Most Were Rural; In 2012, 

Urban CRNAs Were 

Dominant
 

Page 14 GAO-14-153 Nurse Anesthetists and Medicare

Figure 2: Number of Selected Chronic Pain Procedures Billed by All Providers and 

by Certified Registered Nurse Anesthetists (CRNA) in Urban and in Rural Areas in 

Medicare Fee-for-Service (FFS) from 2009 through 2012

Notes: Provider type is based largely on the specialty indicated on the claim. Because services billed 

“incident to” indicate the specialty of the billing professional, our analysis is based on billing specialty.

To the extent that CRNAs provided services in whole or in part that were billed “incident to” another 

professional, these data may understate the role of CRNAs in the provision of these procedures. 

Additionally, these data are based on provider location, rather than beneficiary residence. Roughly 

0.2 percent of provider locations were uncategorized and are not reflected above.

In rural markets, provider shares followed the national trends. (See fig. 3.)

• Of the chronic pain procedures billed by rural providers, CRNA claims 

were a small percentage.

• Physicians without board certification in pain medicine billed for the 

majority of claims from rural providers; however, this number declined 

over time, while pain physicians billed for an increasing share—almost 

a third of rural claims in 2012.
 

Page 15 GAO-14-153 Nurse Anesthetists and Medicare

Figure 3: Shares of Selected Chronic Pain Procedures in Medicare Fee-for-Service 

(FFS) Furnished in Rural Areas, by Provider Type, 2009 through 2012

Notes: Percentages may not add to 100 due to rounding. Provider type is based largely on the 

specialty indicated on the claim. Because services billed “incident to” indicate the specialty of the 

billing professional, our analysis is based on the billing specialty. To the extent that CRNAs, for 

example, provided services in whole or in part that were billed “incident to” another professional, 

these data may understate the role of CRNAs in the provision of these procedures. Additionally, these 

data are based on provider location, rather than beneficiary residence. Roughly 0.2 percent of 

provider locations were uncategorized and are not reflected above.

a

To identify procedures billed by pain physicians, we cross-referenced the names of physicians listed 

by the American Board of Medical Specialties (ABMS) as board certified in pain medicine to a list of 

all Medicare providers.
 

Page 16 GAO-14-153 Nurse Anesthetists and Medicare

In mid-2011, Noridian began denying certain chronic pain management 

services that were billed by CRNAs and maintained this policy through 

2012. The denial policy, among other factors, had the potential to affect 

beneficiary utilization in the Noridian states where CRNAs billed for 

chronic pain management services. We compared all providers’ billing of 

selected chronic pain procedures in 2010—the year prior to the denial 

policy—with that in 2012—the full year in which the denial policy was in 

place—in the Noridian states with the highest share of CRNAs previously 

billing for these procedures. In 2009, CRNAs billed for 8 percent of the 

selected procedures in Montana, 1.7 percent in Wyoming, and 

1.4 percent in South Dakota.18

The change in chronic procedures billed between 2010 and 2012 was 

minimal for the three states overall, but varied by state.

During that same year, CRNAs accounted 

for 19 percent of selected chronic pain procedures in rural areas of 

Montana, 4 percent in rural Wyoming, and less than 1 percent in rural 

South Dakota.

19

 

18The rest of the Noridian states—Alaska, Arizona, North Dakota, Oregon, and Utah—had 

very few or no CRNA claims. Washington State is also in Noridian’s jurisdiction; however, 

because CRNAs in Washington are dually trained and certified as NPs, the denials did not 

apply to them. In addition, Idaho Part B was under another contract until 2011. For these 

reasons, we did not include Washington or Idaho in our analysis of Noridian states.

In 2010, 

providers in those states billed for 28,238 selected chronic pain 

procedures—of which CRNAs accounted for 2.6 percent—and they billed 

for 28,155 procedures in 2012 when Noridian denied CRNA claims for 

these procedures. By state, the number of procedures billed by South 

Dakota and Wyoming providers declined by 9.2 percent and 6.7 percent, 

respectively, while Montana provider claims grew by 14 percent over the 

2-year period. (See fig. 4.)

19In contrast, from 2009 through 2012, the number of selected procedures billed to 

Medicare FFS increased continuously nationwide (as shown in app. II).

After Noridian Began 

Denying CRNA 

Claims, Changes in 

the Number of 

Chronic Pain 

Procedures Billed 

Varied across Three 

Selected States
 

Page 17 GAO-14-153 Nurse Anesthetists and Medicare

Figure 4: Number of Selected Chronic Pain Procedures Billed to Medicare Fee-forService (FFS) in Montana, South Dakota, and Wyoming, 2009 through 2012

Notes: The Noridian denial policy was implemented during 2011, and was fully implemented in 2012. 

Additionally, these data are based on provider location, rather than beneficiary residence.

Among rural providers in Montana, South Dakota, and Wyoming, 

aggregate billing for selected chronic pain procedures declined between 

2010 and 2012, but by state, the changes varied.20

 

20In contrast, from 2009 through 2012, the number of procedures billed by rural providers 

to Medicare FFS increased continuously nationwide (as shown in fig. 2).

(See fig. 5.) In 2010, 

rural providers in those states billed for 9,247 selected chronic pain 

procedures, of which CRNAs accounted for 7.4 percent. In 2012, rural 

providers in those states billed for just over 8,000 selected procedures, a 

13 percent decline from 2010. The drop in the aggregate number of 

procedures billed by rural providers in those states was largely the result 

of a decline in South Dakota; Montana and Wyoming showed only a slight 

decline in billing.
 

Page 18 GAO-14-153 Nurse Anesthetists and Medicare

Figure 5: Number of Selected Chronic Pain Procedures Billed to Medicare Fee-forService (FFS) by Rural Providers in Montana, South Dakota, and Wyoming, 2009 

through 2012

Notes: The Noridian denial policy was implemented during 2011, and was fully implemented in 2012. 

Additionally, these data are based on provider location, rather than beneficiary residence. Roughly 

0.3 percent of provider locations were uncategorized and are not reflected above.
 

Page 19 GAO-14-153 Nurse Anesthetists and Medicare

Nearly all MACs allowed Medicare payment to CRNAs for some, or all, 

selected chronic pain procedures. As of April 2013, six of the nine MACs 

had uniform payment policies for CRNA-provided chronic pain procedures 

across all states within a jurisdiction. The remaining three MACs varied 

their policies for one state within a jurisdiction. At the state level, MACs 

reported the following payment policies regarding chronic pain 

procedures (see fig. 6):

• allowed payment to CRNAs for all selected procedures in 19 states,

• allowed payment to CRNAs for a subset of selected procedures in 

30 states and the District of Columbia, and

• denied payment to CRNAs for all selected procedures in the 

remaining state.

As of Early 2013, 

MACs Allowed 

Payment to CRNAs 

for All or Some 

Selected Chronic 

Pain Procedures in All 

but One State and for 

E/M Services in 

Roughly Half of the 

States
 

Page 20 GAO-14-153 Nurse Anesthetists and Medicare

Figure 6: Medicare Fee-for-Service (FFS) Payment Policies for Selected Certified Registered Nurse Anesthetist (CRNA)-

Provided Chronic Pain Procedures, by State, April 2013

Notes: Our selected chronic pain procedures were trigger point injections, epidural injections, 

transforaminal epidural injections, somatic nerve blocks, autonomic nerve blocks, paravertebral facet 

joint injections, and facet neurolytic destruction. Generally, a single MAC maintains both the Medicare 

Part A and Medicare Part B contracts for each state; however, as of April 2013, Minnesota, 

Wisconsin, and Illinois had separate MACs for Medicare Part A and Medicare Part B. For these 

states, the figure represents the payment policies for the MAC holding the state’s Medicare Part B 

contract. As of December 2013, the following states have undergone a change in MAC since our data 

collection, which may affect their payment policy: California, Hawaii, Illinois, Maine, Massachusetts, 

Minnesota, Nevada, New Hampshire, Rhode Island, Vermont, and Wisconsin.
 

Page 21 GAO-14-153 Nurse Anesthetists and Medicare

In the 30 states and the District of Columbia where MACs allowed 

payment to CRNAs for only certain chronic pain procedures, MAC 

payment policies indicated substantial variation in the specific procedures 

that can and cannot be billed. MACs most commonly denied CRNA 

payment for trigger point injections and facet neurolytic destruction, 

allowing CRNA payment for these procedures in only two states. 

Conversely, MACs allowed CRNAs payment for somatic nerve blocks in 

20 states and epidural injections in 16 states. Furthermore, because each 

procedure can have multiple CPT codes associated with it, MACs may 

choose to only allow CRNAs payment for some of the CPT codes 

associated with the procedure and not others. This was the case for 

epidural injections, transforaminal epidural injections, autonomic nerve 

blocks, and somatic nerve blocks. Figure 7 illustrates the variation in MAC 

payment policies for selected CRNA-provided chronic pain procedures in 

Florida, Nevada, and Pennsylvania.

Figure 7: Medicare Fee-for-Service (FFS) Payment Policies for Selected Certified 

Registered Nurse Anesthetist (CRNA)-Provided Chronic Pain Procedures in Florida, 

Nevada, and Pennsylvania, April 2013

Note: CPT is a uniform coding system maintained by the American Medical Association used to 

identify and bill for medical procedures and services under public and private health insurance 

programs. A given procedure may have several CPT codes that, for instance, may indicate where on 

the body the procedure takes place or whether additional levels of a procedure were performed.
 

Page 22 GAO-14-153 Nurse Anesthetists and Medicare

In contrast to their policies on chronic pain procedures, MACs were

generally more restrictive regarding payment for CRNA-billed E/M 

services. As of April 2013, they reported the following payment policies 

for E/M services (see fig. 8):

• allowed payment to CRNAs for E/M services in 24 states, and

• denied payment to CRNAs for E/M services in 26 states and the 

District of Columbia.
 

Page 23 GAO-14-153 Nurse Anesthetists and Medicare

Figure 8: Medicare Fee-for-Service (FFS) Payment Policies for Certified Registered Nurse Anesthetist (CRNA)-Provided 

Evaluation and Management (E/M) Services, by State, April 2013

Notes: Generally, a single MAC maintains both the Medicare Part A and Medicare Part B contracts 

for each state; however, as of April 2013, Minnesota, Wisconsin, and Illinois had separate MACs for 

Medicare Part A and Medicare Part B. For these states, the figure represents the payment policies for 

the MAC holding the state’s Medicare Part B contract. As of December 2013, the following states 

have undergone a change in MAC since our data collection, which may affect their payment policy: 

California, Hawaii, Illinois, Maine, Massachusetts, Minnesota, Nevada, New Hampshire, Rhode 

Island, Vermont, and Wisconsin.
 

Page 24 GAO-14-153 Nurse Anesthetists and Medicare

Payment policies for CRNA-provided chronic pain procedures did not 

always align with payment policies for E/M services. In the 19 states 

where MACs reported that they allowed payment to CRNAs for all chronic 

pain procedures, they also allowed payment to CRNAs for E/M services.

However, among the 30 states for which MACs told us that they allowed

payment to CRNAs for only certain procedures, MACs indicated that they 

allowed payment for E/M services in 5—California, Florida, Hawaii, 

Kentucky, and Nevada—while denying payment for E/M services in the 

remaining states and the District of Columbia.

The MACs did not implement CMS’s CRNA payment policy consistently; 

three MACs took steps to apply the policy in 2013, while the remaining six 

MACs did not. MACs pointed to a number of challenges, including 

vagueness in state scope of practice laws, that affected their ability to 

implement the policy.

Three MACs took steps to implement CMS’s 2013 rule on CRNA 

payment and updated their CRNA payment policies, when necessary. 

CMS officials told us that they rely on MACs to determine whether 

CRNAs are allowed to provide specific services by reviewing each state’s 

CRNA scope of practice laws. Two MACs made an effort to determine 

which services CRNAs are allowed to perform under each state’s scope 

of practice laws. One of the two MACs directly reviewed the laws of the 

states in its jurisdiction, while the other MAC contacted each state to ask 

for its interpretation of the laws. Instead of attempting to interpret state 

scope of practice laws, a third MAC posted a new educational article on 

its website notifying CRNAs that they are responsible for knowing which 

services are allowable under their state laws.

The remaining six MACs did not take steps to revisit their CRNA payment 

policies for 2013. Three of the six MACs reviewed the scope of practice 

laws for a state in their jurisdictions prior to CMS’s 2013 ruling at the 

request of the state or provider groups. For instance, one MAC stated that 

when it began its contract in 2009, the CRNA association for one of its 

states asked the MAC to consider allowing its CRNAs to be paid for 

chronic pain services, citing a long-standing history of providing these 

services. At that time, the MAC reviewed the state’s CRNA scope of 

practice laws and determined that they did not preclude CRNAs from 

Faced with 

Challenges, MACs 

Inconsistently 

Implemented CMS’s 

CRNA Payment 

Policy

Three MACs Took Steps to 

Implement CMS Policy, 

While Remaining Six Did 

Not Revisit Payment 

Policies for 2013
 

Page 25 GAO-14-153 Nurse Anesthetists and Medicare

providing chronic pain services. It then extended this affirmative payment 

policy across all states within its jurisdiction without reviewing further state 

laws. When asked about its implementation of CMS’s 2013 CRNA 

payment policy, this MAC told us that it had not revisited any state scope 

of practice laws.

Two of the six MACs reported that they have overarching policies in place 

to determine coverage for all nonphysician provider types and, therefore, 

have not taken any steps to implement this latest CRNA payment policy. 

For example, one of these MACs noted that nonphysician providers must 

submit a request to the MAC to receive payment for a specific CPT code. 

The MAC will then review the relevant state scope of practice law and 

determine whether to allow payment for that code. The remaining MAC 

reported that it was waiting for further instructions from CMS before 

implementing the policy.

MACs discussed a variety of challenges that affected their 

implementation of CMS’s CRNA payment policy. Most MACs reported 

challenges interpreting state scope of practice laws to make 

determinations about which services CRNAs are allowed to provide, 

noting that state scope of practice laws are generally vague and lack 

details about which specific services CRNAs can perform.21

 

21In 2000, we reported that, for NPs and clinical nurse specialists, state laws varied in 

both the services these practitioners were allowed to provide and the settings in which 

they could provide the services. We stated that, because the Medicare program did not 

maintain information on what each state allows, providers may be reimbursed for services 

that are not within their allowed scope of practice. We noted that a federal advisory group 

recommended a survey of states to establish a national database of allowable practices, 

and work with national accreditation bodies to establish standard minimum scopes of 

practice. See GAO, Medicare: Lessons Learned from HCFA’s Implementation of Changes 

to Benefits, 

MACs that 

asked states to provide an interpretation of the scope of practice laws 

reported that the states generally were unable to provide definitive 

responses. For instance, one MAC that looked into a state’s CRNA scope 

of practice in 2010 told us that the process to determine whether the state 

law allowed CRNAs to perform chronic pain services was convoluted; the 

GAO/HEHS-00-31 (Washington, D.C.: Jan. 25, 2000). In a 2001 50-state 

review of state scope of practice laws for NPs, PAs, and clinical nurse specialists, the 

HHS Office of Inspector General found that the state scope of practice laws were broad 

and, as a result, provided little guidance that contractors could use to process claims. See: 

HHS Office of Inspector General, Medicare Coverage of Non-Physician Practitioner 

Services, OEI-02-00-00290 (June 2001).

MACs Reported Difficulty 

in Interpreting State Scope 

of Practice Laws and 

Other Constraints
 

Page 26 GAO-14-153 Nurse Anesthetists and Medicare

MAC was directed back and forth between many state and federal 

officials and provider groups. Another MAC said that when a 

determination could not be made about a state’s scope of practice, it 

defaulted to allowing payment for all services approved by the AANA.

A few MACs discussed the difficulty of differentiating between acute and 

chronic pain services for payment purposes. Because CPT codes for 

services used to treat chronic pain are also used to bill for acute pain care 

in the peri-operative setting, one MAC told us that the only definitive way 

to determine whether the service was for chronic or acute pain is to 

review the medical record. However, some MACs explained that since 

chronic pain procedures are typically provided in an outpatient setting, 

they can rely on the place of service listed on the claim to make a best 

guess at whether the procedure was used to treat chronic pain. In 

addition, a few MACs noted that the frequency of the service can also be 

an indicator, with multiple injections billed for a patient by the same 

provider over a period of time indicating that the procedure was likely 

used to treat chronic pain.

Two MACs assumed that Medicare’s rule requiring physician supervision 

of anesthesia services provided by CRNAs in hospital and ASC settings 

applied to chronic pain services in all settings; this assumption has 

potential implications for CRNA billing of chronic pain services. Under this 

rule, CRNA-provided anesthesia services furnished in hospital and ASC 

settings must be performed under the direction of a physician unless a 

state’s governor has opted out of this requirement.22

 

2242 C.F.R. 482.52.

CMS guidance 

clarifies that this requirement applies to anesthesia services and not to 

analgesia services, which are defined to include services used to dull or 

alleviate pain without other effects, such as the loss of consciousness; the 

guidance does not expressly use the term “chronic pain management.” 

These two MACs took the view that they would have needed to review 

CRNA scope of practice laws only in states that had opted-out of the 

supervision requirement, implying that they considered chronic pain 

management services to be anesthesia services. Regardless of the 

validity of this interpretation, the supervision rule only applies in hospital 

and ASC settings, not office settings. By applying this rule to office 

settings, these MACs may have unnecessarily restricted the services for 
 

Page 27 GAO-14-153 Nurse Anesthetists and Medicare

which CRNAs in 10 of the states under these MACs’ jurisdictions are 

allowed to bill.

Use of state scope of practice laws to govern Medicare coverage of 

CRNA-provided chronic pain care continues to be an area of uncertainty 

and confusion for many MACs. Similarly, certain MACs have interpreted 

the CRNA supervision rule, as it relates to CRNA-provided chronic pain 

management services, in a way that may inappropriately limit CRNA 

billing for such services when furnished in office settings. As a result, 

MACs have not implemented CMS’s 2013 payment rule in a consistent 

manner that ensures appropriate beneficiary coverage and provider 

payment. Although CRNAs do not bill for a significant share of the chronic 

pain procedures we reviewed, if a MAC improperly denies payment to 

CRNAs in a state that allows CRNAs to independently furnish such 

services, beneficiary access to these services may be unnecessarily 

affected.

In order to ensure consistent implementation of CRNA payment policy, 

we recommend that the Administrator of CMS (1) provide specific 

instructions to MACs on how to determine coverage with reference to a 

state’s scope of practice laws, including instructions on how to proceed if 

the state scope of practice laws are not explicit, and (2) clarify the 

applicability of the CRNA supervision rule to payment for CRNA-provided 

chronic pain management services.

We provided a draft of this report to HHS for comment. In its written 

response, reproduced in appendix IV, HHS concurred with our two 

recommendations. Regarding our recommendation to provide specific 

instructions to MACs on how to determine coverage with reference to a 

state’s scope of practice laws, HHS stated that CMS plans to send a letter 

directing all MACs to seek clarification from appropriate state officials or 

entities if state scope of practice laws are not explicit. Regarding our 

recommendation to clarify the applicability of the CRNA supervision rule 

to payment for CRNA-provided chronic pain management services, HHS 

stated that CMS will clarify that the supervision rule governs only 

anesthesia services furnished in hospitals or ASCs. HHS also provided 

technical comments that we incorporated as appropriate.

Conclusion

Recommendations for 

Executive Action

Agency Comments 

and Our Evaluation
 

Page 28 GAO-14-153 Nurse Anesthetists and Medicare

As agreed with your offices, unless you publicly announce the contents of 

this report earlier, we plan no further distribution of it until 30 days from its 

date. At that time, we will send copies to the Secretary of Health and 

Human Services. In addition, the report will be available at no charge on 

the GAO website at http://www.gao.gov.

If you or your staffs have any questions about this report, please contact 

me at (202) 512-7114 or cosgrovej@gao.gov. Contact points for our 

Offices of Congressional Relations and Public Affairs may be found on 

the last page of this report. GAO staff who made key contributions to this

report are listed in appendix V.

James Cosgrove

Director, Health Care
Appendix I: Scope and Methodology

Page 29 GAO-14-153 Nurse Anesthetists and Medicare

This appendix describes our methodology for analyzing recent trends in 

billing for selected chronic pain procedures, as well as changes in the 

number of procedures billed during the period of Noridian Healthcare 

Solutions (Noridian) denials. It also describes our efforts to ensure the 

reliability of the data.

We focused our review on a set of seven categories of chronic pain 

procedures and corresponding current procedural terminology (CPT) 

codes. To select procedures, we obtained an American Association of 

Nurse Anesthetists (AANA) list of CPT codes that are billed by certified 

registered nurse anesthetists (CRNA). We categorized the CPT codes by 

procedure, in consultation with nurse and physician pain experts. We 

narrowed this list to procedures that were either reported by a Medicare 

Administrative Contractor (MAC) billing specialist as most likely to be 

used in treating chronic pain (as opposed to acute pain), or those 

commonly mentioned across payer resources—such as local coverage 

determinations (LCD)—as pain management options. We excluded other 

types of chronic pain management services, such as evaluation and 

management (E/M) and pharmacological services because of the 

unavailability of reliable data. The procedures we selected to include 

were:

• autonomic nerve blocks,

• epidural injections,

• facet neurolytic destruction,

• paravertebral facet joint injections,

• somatic nerve blocks,1

• transforaminal epidural injections,2

• trigger point injections.

and

 

1

This category excludes injections for the facial nerve and for digital nerves, such as 

treatment for Morton’s Neuroma.

2

This category excludes codes used for emerging technologies, services, or procedures.

Appendix I: Scope and Methodology

Selection of 

Procedures
Appendix I: Scope and Methodology

Page 30 GAO-14-153 Nurse Anesthetists and Medicare

To determine trends in billing for the selected procedures, we analyzed 

100 percent of Medicare fee-for-service (FFS) paid claims from 2009 

through 2012.3

We took additional steps in an effort to narrow our focus to procedures 

used to treat chronic pain. First, we excluded claims for procedures billed 

as distinct procedural services during the same encounter as another 

procedural service, where normally both would not be billable. We 

confirmed with several Medicare or chronic pain billing experts that, while 

not exclusively, these procedures are more likely than not to be for acute 

pain occurring in conjunction with another procedure. Additionally, we 

excluded claims in the carrier/physician file for procedures performed in 

the hospital inpatient setting. Several MACs told us that chronic pain is 

treated almost exclusively in outpatient settings. While these steps 

mitigated overcounting the number of chronic pain procedures, our 

analysis may still include some acute procedures and may exclude some 

chronic procedures.

We calculated the number of procedures billed to 

Medicare FFS from the carrier/physician file, excluding claims billed by 

some critical access hospitals. We considered procedures administered 

on more than one vertebral level of the spine to be separate procedures. 

We derived overall expenditures for selected chronic pain procedures 

from both provider payments (through the physician/carrier file) and 

outpatient facility payments (through the outpatient file).

We disaggregated biller (provider) type based largely on the provider 

specialty indicated on the claim.4

 

3

We selected this period because Medicare’s current provider identification system was 

fully implemented in mid-2008, and 2012 data were the most recent data at the time of our 

analysis.

The exception to this is the pain 

physician biller type. To identify physicians that are board certified in pain 

medicine—pain physicians—we cross-referenced the names of 

physicians provided by the American Board of Medical Specialties 

(ABMS) as board certified in pain medicine, to a list of all Medicare 

providers, as maintained by the Centers for Medicare & Medicaid 

Services (CMS) through the National Plan and Provider Enumeration 

4

The “other physician” category includes any physician that is not board certified in pain 

medicine; these can include generalists, such as family practice and internal medicine, as 

well as specialists, such as anesthesiologists and sports medicine physicians.

Analysis of Medicare 

Claims Data
Appendix I: Scope and Methodology

Page 31 GAO-14-153 Nurse Anesthetists and Medicare

System (NPPES).5

Our count of procedures provided by nonphysicians may be conservative. 

For example, physicians and certain other providers may bill “incident 

to”—whereby, for example, a physician might bill for a supervised service 

or procedure furnished by a nurse practitioner (NP), physician assistant 

(PA), or CRNA. There is no way on the claim to determine when a service 

is billed “incident to,” rather than provided completely by the billing 

professional. Services billed “incident to” indicate the specialty of the 

billing professional. To the extent that nonphysician professionals 

provided services in whole or in part that were billed “incident to” another 

professional, we may have undercounted procedures provided by 

CRNAs, NPs, or PAs. In addition, providers, including pain physicians, 

can reassign their billing so that their employer may bill on their behalf. In 

this case, the provider identifier on the claim would be that of the 

employer, and we would not capture the provider as a pain physician 

based on our name matching strategy.

Using a name-matching strategy, we were able to 

match 91 percent of the pain physicians to NPPES records. We then 

used the provider identifier from the NPPES data to identify pain 

physicians on the claims.

We also disaggregated the data by geographic location. To analyze urban 

and rural biller (provider) status, we used the CMS Core-Based Statistical 

Area crosswalk to identify those rural providers as providers with a zip 

code that is not associated with a Core-Based Statistical Area.

To determine the extent to which the number of selected chronic pain 

procedures billed to Medicare FFS changed during the period of denials, 

we analyzed Medicare FFS claims from 2009 through 2012 in those 

states under Noridian’s jurisdiction that were subject to CRNA denials and 

under Noridian’s jurisdiction for all 4 years of the study period. At the time 

of our analysis, Noridian’s jurisdiction included Alaska, Arizona, Idaho, 

Montana, North Dakota, Oregon, South Dakota, Utah, Washington, and 

Wyoming. We excluded Washington state, where CRNAs are dually 

trained as NPs, and thus not subject to the denials. We also excluded 

Idaho because it was under another contract until 2011. We then limited 

 

5

Specifically, the names were provided by the ABMS boards that certify in pain medicine: 

the American Board of Anesthesiology, the American Board of Physical Medicine and 

Rehabilitation, and the American Board of Psychiatry and Neurology.

Changes in Billing 

during the Period of 

Noridian Denials
Appendix I: Scope and Methodology

Page 32 GAO-14-153 Nurse Anesthetists and Medicare

our analysis to those states where CRNAs constituted at least 1 percent 

of the chronic pain provider market in 2009: Montana, South Dakota, and 

Wyoming. We measured the overall number of procedures billed to 

Noridian for the same set of selected chronic pain procedures, using the 

same methodology as in the broader trend analysis. We compared billing 

for selected chronic pain procedures prior to the MAC denials—which 

began in 2011—to billing in 2012 when the MAC denial policy was fully 

implemented. We assessed the trend both state-wide and in rural areas.

We ensured the reliability of the Medicare claims data, ABMS pain 

physician data, and NPPES data used in this report by performing 

appropriate electronic data checks, reviewing relevant documentation, 

and interviewing officials and representatives knowledgeable about the 

data. We found the data were sufficiently reliable for the purpose of our 

analyses.

We conducted this performance audit from March 2013 through February 

2014 in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on audit objectives. We believe that 

the evidence obtained provides a reasonable basis for our findings and 

conclusions based on our audit objectives.

Data Reliability and 

Audit Standards
Appendix II: Overall Trends in Billing by 

Selected Procedure

Page 33 GAO-14-153 Nurse Anesthetists and Medicare

From 2009 through 2012, the number of selected chronic pain procedures 

billed to Medicare fee-for-service (FFS) grew by about 5.7 percent 

annually, while Medicare spending on these procedures grew at a slightly 

higher rate. (See tables 4 and 5.) Growth rates varied across procedures; 

for example, claims for somatic nerve blocks and paravertebral facet joint 

injections rose more rapidly at about 11 percent and 9 percent per year, 

respectively, while claims for epidural injections rose by about 2 percent 

annually.

Table 4: Number of Procedures Billed and Average Annual Growth Rate for 

Selected Chronic Pain Procedures in Medicare Fee-for-Service (FFS), 2009 through 

2012

Procedures billed 

(in thousands)

Selected chronic pain procedure 2009 2010 2011 2012

Average 

annual 

growth rate 

(percent)

Autonomic nerve blocks 27 28 29 30 4.30%

Epidural injections 1,008 1,014 1,049 1,069 1.98

Facet neurolytic destruction 312 323 348 374 6.31

Paravertebral facet joint injections 1,028 1,164 1,240 1,317 8.61

Somatic nerve blocks 267 274 287 368 11.25

Transforaminal injections 950 1,028 1,069 1,073 4.16

Trigger point injections 352 362 390 421 6.09

Total 3,945 4,192 4,412 4,654 5.67%

Source: GAO analysis of Centers for Medicare & Medicaid Services (CMS) data.

Overall, Medicare payments for selected chronic pain procedures 

increased somewhat faster than the number billed, rising 6.5 percent 

annually between 2009 and 2012. (See table 5.) This rate of growth is 

above the average growth rate of 5.3 percent per year in overall Medicare 

Part B spending over the same period.1

 

1

See The Boards of Trustees, 2010 Annual Report of the Boards of Trustees of the 

Federal Hospital Insurance and Federal Supplementary Medical Insurance Trust Funds

(Washington, D.C.: August 2010); and 2013 Annual Report of the Boards of Trustees of 

the Federal Hospital Insurance and Federal Supplementary Medical Insurance Trust 

Funds (Washington, D.C.: May 2013).

As with the trend in the number 

billed, average annual growth in expenditures varied across selected 

Appendix II: Overall Trends in Billing by 

Selected Procedure
Appendix II: Overall Trends in Billing by 

Selected Procedure

Page 34 GAO-14-153 Nurse Anesthetists and Medicare

chronic pain procedures; expenditures grew most rapidly for somatic 

nerve blocks (20 percent annually) and facet neurolytic destruction 

(13 percent annually), while expenditures for epidural injections grew 

least rapidly (5 percent annually).

Table 5: Payments and Growth Rates for Selected Chronic Pain Procedures in 

Medicare Fee-for-Service (FFS), 2009 through 2012

Payments 

(dollars in millions) 

Selected chronic pain procedure 2009 2010 2011 2012

Average 

annual 

growth rate 

(percent)

Autonomic nerve blocks $6.2 $6.3 $7.2 $7.5 6.30%

Epidural injections 297.0 301.2 329.0 339.6 4.56

Facet neurolytic destruction 107.9 112.7 130.7 156.2 13.13

Paravertebral facet joint injections 227.1 207.2 238.7 261.0 4.74

Somatic nerve blocks 26.4 28.9 34.3 45.6 20.04

Transforaminal injections 243.8 268.0 276.5 284.7 5.30

Trigger point injections 16.9 18.2 21.0 23.6 11.75

Total $925.3 $942.5 $1,037.4 $1,118.0 6.51%

Source: GAO analysis of Centers for Medicare & Medicaid Services (CMS) data.
Appendix III: CRNA Share of Selected Chronic 

Pain Procedures, by State

Page 35 GAO-14-153 Nurse Anesthetists and Medicare

This appendix provides further detail on how certified registered nurse 

anesthetists’ (CRNA) market share of selected chronic pain procedures 

changed between 2009 and 2012, by state.

Table 6: Certified Registered Nurse Anesthetist (CRNA) Market Share for Selected 

Chronic Pain Procedures in Medicare Fee-for-Service (FFS), by State, 2009 and 2012

Percentage of procedures 

billed by certified registered 

nurse anesthetists

State 2009 2012

Percentage point change 

from 2009 through 2012

New Hampshire 1.11% 5.50% 4.39

Tennessee 0.96 3.48 2.52

Mississippi 0.08 0.51 0.43

Wisconsin 0.19 0.41 0.22

Kansas 3.82 4.03 0.21

Illinois 0.32 0.53 0.21

Alabama 0.02 0.09 0.07

Michigan 0.18 0.22 0.04

Hawaii 0.00 0.03 0.03

Nevada 0.15 0.17 0.02

Indiana 0.05 0.07 0.02

Arkansas 0.08 0.09 0.01

Georgia 0.01 0.02 0.01

Virginia 0.00 0.01 0.01

Maine 0.01 0.02 0.01

Florida 0.01 0.01 0.00

Maryland 0.00 0.00 0.00

South Carolina 0.00 0.00 0.00

Ohio 0.00 0.00 0.00

Delaware 0.00 0.00 0.00

District of Columbia 0.00 0.00 0.00

Massachusetts 0.00 0.00 0.00

New Jersey 0.00 0.00 0.00

North Dakota 0.00 0.00 0.00

Rhode Island 0.00 0.00 0.00

Vermont 0.00 0.00 0.00

West Virginia 0.00 0.00 0.00

Louisiana 0.02 0.01 -0.01

Appendix III: CRNA Share of Selected 

Chronic Pain Procedures, by State
Appendix III: CRNA Share of Selected Chronic 

Pain Procedures, by State

Page 36 GAO-14-153 Nurse Anesthetists and Medicare

Percentage of procedures 

billed by certified registered 

nurse anesthetists

State 2009 2012

Percentage point change 

from 2009 through 2012

Connecticut 0.01 0.00 -0.01

New York 0.02 0.01 -0.01

North Carolina 0.01 0.00 -0.01

Pennsylvania 0.02 0.00 -0.02

California 0.06 0.02 -0.04

Alaska 0.12 0.00 -0.12

Utah 0.15 0.00 -0.15

Texas 0.30 0.15 -0.15

Oklahoma 1.42 1.16 -0.26

Washington 0.78 0.52 -0.26

Missouri 0.42 0.11 -0.31

Kentucky 0.86 0.54 -0.32

Idaho 1.07 0.63 -0.44

Oregon 0.56 0.00 -0.56

Colorado 0.88 0.18 -0.70

Minnesota 2.64 1.93 -0.71

Arizona 0.82 0.00 -0.82

New Mexico 1.36 0.28 -1.08

South Dakota 1.35 0.00 -1.35

Wyoming 1.61 0.02 -1.59

Nebraska 4.23 2.62 -1.61

Iowa 7.27 4.30 -2.97

Montana 8.08 0.26 -7.82

Source: GAO analysis of Centers for Medicare & Medicaid Services (CMS) data.

Notes: The CRNA provider type is based on the specialty indicated on the claim. Because claims for 

services billed “incident to” indicate the specialty of the billing professional, our analysis is based on 

the billing specialty. To the extent that CRNAs provided services in whole or in part that were billed

“incident to” another professional, these data may understate the role of CRNAs in the provision of 

these procedures. Additionally, these data are based on provider location, rather than beneficiary 

residence.
Appendix IV: Comments from the Department 

of Health and Human Services

Page 37 GAO-14-153 Nurse Anesthetists and Medicare

Appendix IV: Comments from the 

Department of Health and Human Services
Appendix IV: Comments from the Department 

of Health and Human Services

Page 38 GAO-14-153 Nurse Anesthetists and Medicare
Appendix IV: Comments from the Department 

of Health and Human Services

Page 39 GAO-14-153 Nurse Anesthetists and Medicare
Appendix V: GAO Contact and Staff 

Acknowledgments

Page 40 GAO-14-153 Nurse Anesthetists and Medicare

James Cosgrove, (202) 512-7114 or cosgrovej@gao.gov

In addition to the contact named above, Rosamond Katz, Assistant 

Director; Sandra C. George; Richard Lipinski; Kate Nast; and 

Kathryn Richter made key contributions to this report.

Appendix V: GAO Contact and Staff 

Acknowledgments

GAO Contact

Staff

Acknowledgments

(291113)
The Government Accountability Office, the audit, evaluation, and 

investigative arm of Congress, exists to support Congress in meeting its 

constitutional responsibilities and to help improve the performance and 

accountability of the federal government for the American people. GAO 

examines the use of public funds; evaluates federal programs and 

policies; and provides analyses, recommendations, and other assistance 

to help Congress make informed oversight, policy, and funding decisions. 

GAO’s commitment to good government is reflected in its core values of 

accountability, integrity, and reliability.

The fastest and easiest way to obtain copies of GAO documents at no 

cost is through GAO’s website (http://www.gao.gov). Each weekday 

afternoon, GAO posts on its website newly released reports, testimony, 

and correspondence. To have GAO e-mail you a list of newly posted 

products, go to http://www.gao.gov and select “E-mail Updates.”

The price of each GAO publication reflects GAO’s actual cost of 

production and distribution and depends on the number of pages in the 

publication and whether the publication is printed in color or black and 

white. Pricing and ordering information is posted on GAO’s website, 

http://www.gao.gov/ordering.htm. 

Place orders by calling (202) 512-6000, toll free (866) 801-7077, or 

TDD (202) 512-2537. 

Orders may be paid for using American Express, Discover Card, 

MasterCard, Visa, check, or money order. Call for additional information.

Connect with GAO on Facebook, Flickr, Twitter, and YouTube. 

Subscribe to our RSS Feeds or E-mail Updates. Listen to our Podcasts. 

Visit GAO on the web at www.gao.gov. 

Contact:

Website: http://www.gao.gov/fraudnet/fraudnet.htm

E-mail: fraudnet@gao.gov

Automated answering system: (800) 424-5454 or (202) 512-7470

Katherine Siggerud, Managing Director, siggerudk@gao.gov, (202) 512-

4400, U.S. Government Accountability Office, 441 G Street NW, Room 

7125, Washington, DC 20548

Chuck Young, Managing Director, youngc1@gao.gov, (202) 512-4800

U.S. Government Accountability Office, 441 G Street NW, Room 7149 

Washington, DC 20548

GAO’s Mission

Obtaining Copies of 

GAO Reports and 

Testimony

Order by Phone

Connect with GAO

To Report Fraud, 

Waste, and Abuse in 

Federal Programs

Congressional 

Relations

Public Affairs

Please Print on Recycled Paper.