| Acronym | Term |
| AARP | American Association of Retired Persons |
| ABG | Arterial blood gas |
| ABN | Advance Beneficiary Notice of Noncoverage |
| ACH | Acute care hospital |
| ADMC | Advanced determination of Medicare coverage |
| ADP | Automated data processing |
| ADR | Additional development request/additional documentation request |
| AFO | Ankle-foot orthotic |
| AIC | Amount in controversy |
| ALJ | Administrative law judge |
| ALOS | Average length of stay |
| ALS | Amyotrophic lateral sclerosis |
| AMA | American Medical Association |
| ANSI | American National Standards Institute |
| AOB | Assignment of benefits |
| APC | Ambulatory payment classification |
| ARD | Assessment reference date |
| ASC | Ambulatory surgical center |
| ASCA | Administrative Simplification Compliance Act |
| ASP | Average sales price |
| ATP | Assistive technology practitioner |
| ATS | Assistive technology supplier |
| AWP | Average wholesale price |
| BBA | Balanced Budget Act of 1997 |
| BBRA | Balanced Budget Refinement Act of 1999 |
| BE | Benefits exhausted |
| BIB | Break in billing |
| BIPA | Medicare, Medicaid and SCHIP Benefits Improvement and Protection Act of 2000 |
| BIS | Break in service (break-in-service claim) |
| BIU | Benefit Integrity Unit |
| BMM | Bone Mass Measurements |
| CAC | Carrier Advisory Committee |
| CAD | Computer-aided design |
| CAH | Critical access hospital |
| CAM | Computer-aided manufacturing |
| CAPD | Continuous ambulatory peritoneal dialysis |
| CAT | Computerized axial tomography |
| CB | Consolidated billing |
| CBA | Competitive bidding area |
| CBIC | Competitive bidding implementation contractor |
| CBSA | Core-based statistical area |
| CBT | Computer-based training |
| CC | Condition code |
| CCN | Claim control number |
| CCPD | Continuous cycling peritoneal dialysis |
| CCR | Cost-to-charge ratio/Customer Care Representative |
| CDC | CERT Documentation Contractor |
| CDE | Certified diabetic educators |
| CEDI | Common Electronic Data Interchange |
| CELIP | Claim expansion and line item processing |
| CERT | Comprehensive Error Rate Testing |
| CEU | Continuing education units |
| CF | Conversion factor |
| CFO | Chief financial officer |
| CFR | Code of Federal Regulations |
| CHC | Continuous home care |
| CHOW | Change of ownership |
| CLIA | Clinical Laboratory Improvement Amendments |
| CMD | Contractor medical director |
| CMG | Case-mix group |
| CMHC | Community mental health center |
| CMI | Case-mix index |
| CMN | Certificate of Medical Necessity |
| CMR | Comprehensive medical review |
| CMS | Centers for Medicare & Medicaid Services |
| CMS-1696 | Appointment of Representative form |
| CMS-1450 | Uniform Bill (UB-04) (for Part A) |
| CMS-1500 | Health Insurance Claim Form (for Part B and DME) |
| CMS-20034 | Request for Medicare Hearing by an Administrative Law Judge form |
| CMS-382 | ESRD Beneficiary Selection form |
| CMS-5011B | Request for Part B Medicare Hearing by an Administrative Law Judge form |
| CMS-588 | Electronic Funds Transfer (EFT) Authorization Agreement form |
| CMS-855S | Medicare Enrollment Application form |
| CMS-R-131 | Advance Beneficiary Notice of Noncoverage (ABN) form |
| CNM | Certified nurse midwife |
| CNS | Certified nurse specialist |
| CO | Central office (CMS, in Baltimore, MD) |
| CO | Contracting officer |
| COB | Coordination of benefits |
| COBC | Coordination of Benefits Contractor |
| COBRA | Consolidation Omnibus Budget Reconciliation Act of 1986 |
| COLA | Cost of living adjustment |
| COP | Conditions of participation |
| CORF | Comprehensive outpatient rehabilitation facility |
| CP | Clinical psychologist |
| CPI | Consumer price index |
| CPO | Care plan oversight |
| CPT | Claims processing timeliness |
| CPT/CPT-4 | Current procedural terminology |
| CR | Change Request |
| CRC | CERT Review Contractor |
| CRNA | Certified registered nurse anesthetist |
| CSI | Claim Status Inquiry |
| CSW | Clinical social workers |
| CWF | Common Working File (also known as HIMR) |
| DAB | Departmental appeals board |
| DCN | Document control number |
| DDE | Direct Data Entry |
| DGME | Direct graduate medical education |
| DHHS | Department of Health and Human Services (also referred to as HHS) |
| DIF | DME Information Form |
| DME | Durable medical equipment |
| DME MAC | Durable medical equipment Medicare administrative contractor |
| DMECS | Durable Medical Equipment Coding System |
| DMEPOS | Durable medical equipment prosthetics, orthotics, and supplies |
| DMERC | Durable medical equipment regional carrier |
| DO | Doctor of osteopathy |
| DOA | Date of accident/Date of accretion |
| DOB | Date of birth |
| DOD | Date of death |
| DOJ | Department of Justice |
| DOL | Department of Labor |
| DOS | Date of service |
| DPA | Dual Photon Absorptiometry |
| DPM | Doctor of podiatric medicine |
| DPU | Distinct-part unit |
| DRA | Deficit Reduction Act of 2005 |
| DRG | Diagnosis-related group |
| DSH | Disproportionate share hospital |
| DSMT | Diabetes self-management training |
| E&M | Evaluation and management |
| ECT | Electroconvulsive therapy |
| EDI | Electronic data interchange |
| EFT | Electronic funds transfer |
| EGHP | Employer group health plan |
| EIN | Employer Identification Number |
| ELGA | Eligibility Inquiry Part A |
| EMC | Electronic media claim |
| EMR | Electronic medical record |
| EOB | Explanation of benefits |
| EPO | Epoetin |
| ER | Emergency room |
| ERA | Electronic remittance advice |
| ESA | Erythropoiesis stimulating agent |
| ESRD | End-stage renal disease |
| FAQ | Frequently asked question |
| FBI | Federal Bureau of Investigation |
| FCN | Financial control number |
| FDA | Food & Drug Administration |
| FI | Fiscal intermediary |
| FISS | Fiscal Intermediary Standard System (processing system for Part A) |
| FL | Field Locator/Form Locator |
| FMR | Focused medical review |
| FOI | Freedom of Information |
| FOIA | Freedom of Information Act |
| FQHC | Federally qualified health center |
| FY | Fiscal Year |
| GAO | General Accounting Office; or Government Accountability Office |
| GHP | Group health plan |
| GIP | General inpatient care |
| GME | Graduate medical education |
| GPCI | Geographic practice cost index |
| HBV | Hepatitis B Virus |
| HCO | High cost outlier |
| HCPCS | Healthcare Common Procedure Coding System |
| HHA | Home health agency |
| HHPPS | Home health prospective payment system |
| HHRG | Home health resource group |
| HIC | Health Insurance Claim (number) |
| HICN | Health Insurance Claim number |
| HIMR | Health Insurance Master Record (also known as CWF) |
| HIPAA | Health Insurance Portability and Accountability Act |
| HIPPS | Health insurance prospective payment system (code) |
| HIQA | Health Insurance Query Access (CWF) |
| HIQH | Health insurance query for home health agencies |
| HIV | Human Immunodeficiency Virus |
| HME | Home medical equipment |
| HMO | Health maintenance organization |
| HPSA | Health professional shortage area |
| HRSA | Health Resources Services Administration |
| HSQB | Health Standards Quality Bureau |
| I/OCE | Integrated Outpatient Code Editor |
| IACS-PC | Individuals Authorized Access to CMS Computer Services—Provider Community |
| ICD-10-CM | International Classification of Diseases, Clinical Modification, 10th Revision |
| ICD-9-CM | International Classification of Diseases, Clinical Modification, 9th Revision |
| ICN | Internal control number |
| ID | Identification |
| IDG | Interdisciplinary group |
| IDTF | Independent diagnostic testing facility |
| IG | Inspector General |
| IIC | Inflation-indexed charge |
| IME | Indirect medical education |
| IOM | (CMS) Internet-Only Manual |
| IP | Inpatient |
| IPF | Inpatient psychiatric facility |
| IPPE | Initial physical preventive examination |
| IPPS | Inpatient prospective payment system |
| IRF | Inpatient rehabilitation facility |
| IRP | Inexpensive or other routinely purchased DME |
| IRS | Internal Revenue Service |
| IRVEN | Inpatient rehabilitation validation and entry |
| IV | Intravenous |
| IVR | Interactive voice response (system) |
| JSM | Joint Signature Memorandum |
| KAFO | Knee-ankle foot orthotic |
| LCD | Local coverage determination |
| LCL | Lowest charge level |
| LGHP | Large group health plan |
| LIDOS | Line item date of service |
| LIP | Low income payment |
| LOS | Length of stay |
| LPM | Liters per minute |
| LPN | Licensed practical nurse |
| LSO | Lumbar-sacral orthosis |
| LTC DRG | Long-term care diagnosis-related group |
| LTCH | Long-term care hospital |
| LTR | Lifetime reserve (days) |
| LUPA | Low utilization payment adjustment |
| MAC | Medicare administrative contractor |
| MAE | Mobility assistive equipment |
| MAO | Medicare Advantage organization |
| MCE | Medicare code editor |
| MCFU | Medicaid Fraud Control Units |
| MCS | Multi-Carrier System (processing system for Medicare Part B) |
| MD | Doctor of medicine |
| MDH | Medicare dependent hospital |
| MDS | Minimum data set |
| MEDA | Medicare Part A |
| MEDPARD | Medicare Participating Physician/Supplier Directory |
| MHO | Medicare hearing officer |
| MIP | Medicare Integrity Program |
| MMA | Medicare Modernization Act of 2003 |
| MPDIMA | Medicare Prescription Drug, Improvement, and Modernization Act of 2003 |
| MPFS | Medicare physician fee schedule |
| MPFSDB | Medicare physician fee schedule database |
| MQSA | Mammography Quality Standards Act |
| MR | Medical review |
| MREP | Medicare Remit Easy Print (software) |
| MRI | Magnetic resonance imaging |
| MRN | Medicare redetermination notice |
| MSA | Metropolitan statistical area |
| MSN | Medicare Summary Notice |
| MSP | Medicare Secondary Payer |
| MSPRC | Medicare Secondary Payer Recovery Contractor |
| MUE | Medically Unlikely Edit |
| N&AH | Nursing and allied health |
| NCCI | National Correct Coding Initiative |
| NCD | National coverage determination |
| NCPDP | National Council for Prescription Drug Programs |
| NDC | National drug code |
| NF | Nursing facility |
| NHPCS | National Hospice and Palliative Care Organization |
| NOC | Not otherwise classified (code) |
| NOE | Notice of election |
| NON PAR | Nonparticipating provider |
| NOS | Not otherwise specified |
| NP | Nurse practitioner |
| NPI | National Provider Identifier |
| NPP | Nonphysician practitioner |
| NPPES | National Plan and Provider Enumeration System |
| NPWT | Negative pressure wound therapy |
| NSC | National Supplier Clearinghouse |
| NSF | National standard format |
| OAS | Office of Audit Service (of the Department of Health and Human Services) |
| OASIS | Outcome and Assessment Information Set |
| OBRA | Omnibus Budget Reconciliation Act |
| OC | Occurrence code |
| OCE | Outpatient code editor |
| OCIG | Office of Counsel to the Inspector General |
| OD | Optometrist (doctor of optometry) |
| OI | Office of Investigations |
| OIFO | Office of Investigations Field Office (OIG) |
| OIG | Office of Inspector General |
| OMB | Office of Management and Budget |
| OP | Outpatient |
| OPPS | Outpatient prospective payment system |
| ORF | Outpatient rehabilitation facility |
| ORU | Overpayment Recovery Unit |
| OSC | Occurrence span code |
| OSCAR | Online Survey, Certification and Reporting (OSCAR System) |
| OT | Occupational therapist/occupational therapy |
| OTR | On-the-record hearing |
| P&O | Prosthetic and orthotic |
| PA | Physician assistant |
| PA | Policy article |
| PACE | Program of All-Inclusive Care for the Elderly |
| PAI | Patient assessment instrument |
| PAR | Participating provider |
| PCA | Progressive corrective action |
| PCC | Provider contact center |
| PDAC | Pricing, Data Analysis, and Coding (Contractor) |
| PECOS | Provider Enrollment Chain & Ownership System |
| PEN | Parenteral and enteral nutrition |
| PEP | Partial episode payment |
| PHI | Protected health information |
| PHS | Public Health Services |
| PIN | Provider Identification Number |
| PIP | Periodic interim payment |
| PMD | Power mobility device |
| POC | Plan of care |
| POE | Provider outreach and education |
| POS | Place of service |
| POTR | Preliminary on-the-record hearing |
| POV | Power-operated vehicle |
| PPO | Preferred provider organization |
| PPS | Prospective payment system |
| PPTN | Professional Provider Telecommunications Network |
| PPV | Pneumococcal pneumonia vaccine |
| PRM | Provider Reimbursement Manual (Medicare Publication 15-1/15-2) |
| PRRS | Provider relations research specialist |
| PS&R | Provider Statistical & Reimbursement Report |
| PSC | Program safeguard contractor |
| PSC | Patient status code |
| PT | Physical therapist/physical therapy |
| PTAN | Provider Transaction Access Number |
| PWC | Power wheelchair |
| QIC | Qualified independent contractor |
| QIO | Quality improvement organization |
| RA | Remittance advice |
| RAC | Recovery audit contractor |
| RAP | Request for anticipated payment |
| RBRVU | Resource-based relative value unit |
| RC | Revenue code/reason code |
| RDF | Renal dialysis facility |
| RESNA | Rehabilitation Engineering and Assistive Technology of North America |
| RFA | Regulatory Flexibility Act |
| RHC | Rural health clinic |
| RHC | Routine home care |
| RHHI | Regional home health intermediary |
| RIC | Rehabilitation impairment category |
| RICO | Racketeering Influenced Corrupt Organization |
| RN | Registered nurse |
| RNHCI | Religious nonmedical health care institution |
| RO | Regional office (CMS) |
| RRC | Rural Referral Center |
| RTP | Return to provider |
| RUG | Resource utilization group |
| RVU | Relative value unit |
| S/LOC | Status/location |
| SADMERC | Statistical Analysis DMERC (now referred to as the PDAC) |
| SCH | Sole community hospital |
| SCHIP | State Children’s Health Insurance Program |
| SHIP | State Health Insurance Program |
| SLP | Speech-language pathology |
| SNF | Skilled nursing facility |
| SPR | Standard paper remittance |
| SSA | Social Security Administration |
| SSI | Supplemental security income |
| SSN | Social Security Number |
| TEFRA | Tax Equity and Fiscal Responsibility Act of 1982 |
| TENS | Transcutaneous electrical nerve stimulator |
| TIN | Tax Identification Number |
| TLSO | Thoracic-lumbar-sacral orthosis |
| TOB | Type of bill |
| TRU | Telephone reopening unit |
| UB | Uniform bill |
| UPIN | Unique Physician Identification Number |
| VA | Veterans Administration |
| VA | Veterans Affairs |
| VC | Value code |
| VTC | Video teleconference |
| WAC | Wholesale acquisition cost |
| WC | Workers’ compensation |
| YTD | Year to date |