A working reference for the terms, acronyms, and codes that come up daily in medical billing and revenue cycle management. Built by AMS Solutions AAPC-certified team. Bookmark this page for your billing team.
Quick jump: AAPC · Accounts Receivable (A/R) · AWV (Annual Wellness Visit) · BAA (Business Associate Agreement) · CCM (Chronic Care Management) · CCTA (Coronary CT Angiography) · Clean Claim Rate · CMS-1500 · CPT (Current Procedural Terminology) · Denial · DRG (Diagnosis-Related Group) · E/M (Evaluation and Management) · EOB (Explanation of Benefits) · ERA (Electronic Remittance Advice) · ESRD PPS · FFS (Fee for Service) · HCPCS · HIPAA · ICD-10 · ICN (Internal Control Number) · IPPE · LCD (Local Coverage Determination) · MAC (Medicare Administrative Contractor) · MDM (Medical Decision Making) · Modifier · NCD (National Coverage Determination) · Net Collection Rate (NCR) · NPI (National Provider Identifier) · OIG (Office of Inspector General) · PA (Prior Authorization) · PCI (Percutaneous Coronary Intervention) · PIP (Personal Injury Protection) · POS (Place of Service) · Recoupment · RCM (Revenue Cycle Management) · Superbill · Telehealth · TPS (Targeted Probe and Educate) · UB-04 (CMS-1450)
Glossary
AAPC (American Academy of Professional Coders)
The largest professional organization for medical coders. AAPC certification (CPC, COC, CRC, etc.) is the industry-standard credential for billing and coding professionals. AMS uses AAPC-certified coders exclusively.
Accounts Receivable (A/R)
The total amount owed to a healthcare practice for services rendered but not yet collected. A/R aging buckets are typically 0-30, 31-60, 61-90, 91-120, and 120+ days. Healthy practices keep 90+ day A/R below 15%.
AWV (Annual Wellness Visit) (CPT G0438 / G0439)
A Medicare preventive visit billed annually. G0438 is the initial AWV (first one), G0439 is each subsequent AWV. Distinct from preventive E/M (99381-99397) used for non-Medicare patients.
BAA (Business Associate Agreement)
A HIPAA-required contract between a covered entity (practice) and a business associate (billing company, IT vendor, etc.) governing how PHI is used and protected. Required before any PHI is shared.
CCM (Chronic Care Management) (CPT 99490 / 99491)
Monthly time-based codes for managing patients with 2+ chronic conditions. 99490 covers first 20 minutes of staff time. 99491 is 30 minutes of physician time. Requires patient consent and documented care plan.
CCTA (Coronary CT Angiography) (CPT 75571-75574)
A non-invasive cardiac imaging test. Often requires prior authorization. Reimbursement varies significantly by MAC and commercial payer.
Clean Claim Rate
The percentage of claims that pass through payer adjudication without rejection or denial on first submission. Industry average is 85-90%; AMS achieves 95%+.
CMS-1500
The standard professional billing claim form used for physician services. Submitted electronically as ANSI 837P or on paper.
CPT (Current Procedural Terminology)
The medical procedure coding standard maintained by the AMA. Categories: I (procedures, 99202-99499), II (performance measures), III (emerging technology).
Denial
A claim that has been processed by the payer but not paid. Distinct from a rejection (claim never made it past initial validation). Top denial reasons: eligibility, authorization, coding, medical necessity, timely filing.
DRG (Diagnosis-Related Group)
The hospital inpatient prospective payment system grouping. Each DRG has a fixed payment regardless of actual cost.
E/M (Evaluation and Management) (CPT 99202-99499)
Office and outpatient visit codes. Levels 99202-99205 (new patient) and 99212-99215 (established patient) are based on Medical Decision Making (MDM) or time.
EOB (Explanation of Benefits)
A statement from the insurer to the patient explaining what was billed, what was paid, and what the patient owes. Distinct from ERA (which goes to the practice).
ERA (Electronic Remittance Advice) (ANSI 835)
The electronic version of an EOB sent from payer to practice. Contains payment, adjustment, and denial information for reconciliation.
ESRD PPS
End-Stage Renal Disease Prospective Payment System. Bundled payment for dialysis services.
FFS (Fee for Service)
Traditional payment model where providers are paid per service rendered. Distinct from value-based care and capitation models.
HCPCS (Healthcare Common Procedure Coding System)
Codes for non-physician services and supplies. Level I = CPT codes; Level II = J-codes (drugs), G-codes (Medicare), supplies, DME.
HIPAA (Health Insurance Portability and Accountability Act)
Federal law governing the privacy, security, and electronic exchange of Protected Health Information (PHI). All billing companies must comply.
ICD-10 (International Classification of Diseases, 10th Revision)
The diagnostic coding standard. ICD-10-CM for diagnoses, ICD-10-PCS for inpatient procedures. Required on all claims.
ICN (Internal Control Number)
The unique identifier assigned to each claim by the payer for tracking. Critical for appeals and reconciliation. Also called TCN or DCN by some payers.
IPPE (Initial Preventive Physical Examination – CPT G0402)
Medicare Welcome to Medicare visit. Available within first 12 months of Part B enrollment. Distinct from AWV.
LCD (Local Coverage Determination)
Medicare coverage rules set by each MAC. Different MACs have different LCDs for the same service. Practices must follow the LCD for their MAC.
MAC (Medicare Administrative Contractor)
Regional contractors that process Medicare claims. Examples: Novitas (TX, NM, OK, AR, LA, MS, CO), First Coast (FL), NGS (NY, NJ, MA, CT, ME, NH, RI, VT), WPS (IL, MI, MN, WI), Palmetto GBA (NC, SC, VA, WV, GA, AL, TN).
MDM (Medical Decision Making)
The complexity assessment used to determine E/M level. 2021 MDM rules consider: number of problems, data reviewed, and risk of complications.
Modifier
Two-character codes appended to CPT codes to provide additional context. Critical examples: 25 (significant separate E/M), 26 (professional component), 50 (bilateral), 59 (distinct procedural), 76 (repeat), 78 (return to OR), TC (technical component).
NCD (National Coverage Determination)
Medicare coverage rules set at the national level (vs. LCD which is regional). NCDs override LCDs when they conflict.
Net Collection Rate (NCR)
Total payments collected divided by total expected payments (after contractual adjustments). Industry benchmark is 95%+. NCR below 90% indicates revenue leakage.
NPI (National Provider Identifier)
The 10-digit identifier for individual providers (Type 1) and organizations (Type 2). Required on all claims. Issued by CMS via NPPES.
OIG (Office of Inspector General)
The HHS watchdog overseeing Medicare and Medicaid fraud. Maintains the Exclusion List. Practices must screen all providers/staff monthly against the LEIE.
PA (Prior Authorization)
Payer approval required before certain services can be billed. Common for advanced imaging, biologics, infusion therapy, Botox, surgical procedures. Missed PA = automatic denial.
PCI (Percutaneous Coronary Intervention) (CPT 92920-92944)
Catheter-based coronary procedures including stenting and atherectomy. CTO PCI (chronic total occlusion, 92943-92944) requires specific documentation.
PIP (Personal Injury Protection)
No-fault auto insurance coverage. Florida ($10,000, 35-day window), Michigan, NJ, NY, and others have PIP. Specific billing rules differ by state.
POS (Place of Service)
Two-digit code on the claim indicating where the service was rendered. POS 11 = office, POS 19/22 = outpatient hospital, POS 21 = inpatient, POS 02/10 = telehealth.
Recoupment
When a payer takes back previously-paid funds, typically after an audit. Practices have appeal rights but must respond quickly.
RCM (Revenue Cycle Management)
The full lifecycle of a patient encounter from eligibility verification through final payment. Includes scheduling, coding, billing, A/R follow-up, and denial management.
Superbill
The encounter document used by providers to capture CPT/ICD-10 codes for billing. Replaced in many practices by EHR-integrated charge capture.
Telehealth
Remote care delivery. Billed with modifier 95 + POS 10 (home) or POS 02 (other) for synchronous video. Audio-only uses modifier 93 (where allowed).
TPS (Targeted Probe and Educate)
A CMS program where MACs audit a small sample of claims for accuracy. Practices that fail multiple rounds face additional scrutiny.
UB-04 (CMS-1450)
The standard institutional billing claim form (hospitals, SNFs, hospice). Submitted electronically as ANSI 837I.
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