Medical Billing Glossary

Money owed to a healthcare provider for services rendered but not yet collected. AR is tracked in days, with a lower Days in AR indicating faster collections. Industry benchmark is 30–40 days; best-in-class RCM operations achieve under 20 days. Large AR balances signal billing inefficiencies or payer delays.

A change to a patient's account that increases or decreases the outstanding balance. Common adjustments include contractual write-offs (the difference between billed charges and the payer's allowed amount), bad debt write-offs, charity care adjustments, and professional courtesy discounts. Adjustments are not lost revenue — contractual adjustments are expected per payer contracts.

The maximum amount a health insurance plan will pay for a covered service, as established in the provider's contract with that payer. It is also called the eligible expense, negotiated rate, or payment allowance. The provider may not collect more than the allowed amount from the patient and payer combined for in-network services.

A formal request to a payer to reconsider a denied or underpaid claim. Appeals must be submitted within the payer's appeal filing deadline (typically 60–180 days from the denial date) and should include supporting documentation such as medical records, operative notes, or LCD/NCD policy citations. Most payers offer first-level and second-level appeals.

Approval from an insurance company required before certain services, procedures, or medications can be provided. Obtaining prior authorization does not guarantee payment — it must be obtained for the specific service, date range, facility, and rendering provider. Missing or expired authorizations are a leading cause of claim denials.

Billing a patient for the difference between a provider's billed charge and the payer's allowed amount. This practice is prohibited for in-network providers under most contracts and restricted by law in many states. Federal law (the No Surprises Act) limits balance billing in emergency situations and from out-of-network providers at in-network facilities.

A person who receives health insurance benefits under a plan. Also called member, enrollee, or covered person. For Medicare, the term 'beneficiary' specifically refers to the individual enrolled in Medicare Part A or Part B and entitled to receive covered healthcare services.

A HIPAA-required written contract between a covered entity (healthcare provider, health plan, or clearinghouse) and a business associate (any vendor that handles Protected Health Information on the covered entity's behalf). The BAA defines how PHI may be used, specifies safeguards required, and establishes breach notification obligations. Every billing company must have a signed BAA with every client before accessing any patient data.

The practice of grouping related procedures together under a single CPT code rather than billing each component separately. National Correct Coding Initiative (NCCI) edits define which codes are bundled and which can be unbundled with an appropriate modifier. Improperly unbundling codes to increase payment is considered fraudulent billing.

A nonprofit organization that manages the CAQH ProView universal credentialing database, used by most commercial payers to store and access provider credentials. Providers must complete and attest to their CAQH profile regularly (typically every 120 days). An outdated CAQH profile is one of the most common causes of credentialing delays.

The process of recording all billable services rendered to a patient so they can be submitted for reimbursement. Charge capture failures — services performed but never coded or billed — represent lost revenue. Studies estimate that hospitals lose 1–5% of revenue to charge capture errors annually.

A formal request submitted by a healthcare provider to an insurance company requesting payment for services rendered. Claims are submitted electronically via EDI (837 transaction) or on paper (CMS-1500 for professional claims, UB-04 for institutional claims). Each claim includes patient demographics, provider information, diagnosis codes, procedure codes, and billed charges.

An intermediary company that receives electronic claims from healthcare providers, validates them for errors, reformats them to meet payer-specific requirements, and forwards them to the appropriate insurance company. Clearinghouses also return reports on accepted and rejected claims. Major clearinghouses include Change Healthcare, Emdeon, and Availity.

The standard paper claim form used by physicians, non-physician practitioners, and other outpatient providers to bill Medicare, Medicaid, and most commercial insurers for professional services. Named for the Centers for Medicare & Medicaid Services, the current version is the 02/12 revision. The electronic equivalent is the 837P transaction.

The percentage of allowed costs a patient pays for covered services after meeting their deductible. For example, with 80/20 coinsurance, the insurance plan pays 80% and the patient pays 20% of the allowed amount until they reach their out-of-pocket maximum. Coinsurance applies after the deductible is met and differs from copayment.

A fixed amount a patient pays for a specific covered service at the time of service, regardless of the total cost. Copay amounts vary by plan and service type (e.g., $30 for a primary care visit, $75 for a specialist, $150 for urgent care). Copays generally do not count toward the deductible but do count toward the out-of-pocket maximum.

A standardized five-digit code set maintained and annually updated by the American Medical Association (AMA) used to describe medical, surgical, and diagnostic services for billing purposes. CPT codes are divided into three categories: Category I (medical procedures), Category II (performance measures), and Category III (emerging technologies). The codebook is updated every January 1.

The formal process of verifying a healthcare provider's qualifications — medical education, training, licensure, board certifications, malpractice history — and enrolling them with insurance networks to receive reimbursement. Initial credentialing typically takes 60–120 days. Re-credentialing occurs every 2–3 years. Providers cannot bill most payers until credentialing is complete.

Average number of days it takes to collect payment after services are rendered. Calculated as: Total AR Balance ÷ (Total Charges ÷ Number of Days). Industry benchmark: 30–40 days. Best-in-class: under 20 days. Days in AR over 50 indicates serious collection problems. Breaking AR down by payer and aging bucket (0–30, 31–60, 61–90, 90+ days) reveals where collection efforts are needed most.

The amount a patient must pay out-of-pocket annually for covered services before the insurance plan begins to pay its share. Deductibles typically reset on January 1 each year. High-Deductible Health Plans (HDHPs) often pair with Health Savings Accounts (HSAs). Practices should verify how much of a patient's deductible remains at the time of service.

A decision by an insurance company to refuse payment for a submitted claim. Unlike a rejection (which occurs before processing), a denial occurs after adjudication. Common denial reasons include: medical necessity not established, coverage exclusion, duplicate claim, missing prior authorization, timely filing exceeded, and non-covered service. All denials must be worked and either corrected or appealed.

A code from the ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification) system that identifies why a patient sought care. Diagnosis codes determine medical necessity and must directly support the procedures billed. Claims are denied if the diagnosis code does not justify the procedure code submitted.

The calendar date when a medical service was provided to a patient. DOS is used to determine timely filing deadlines, applicable fee schedules, and applicable diagnosis/procedure codes (codes change annually). Billing the wrong DOS is a common but consequential error that can result in denial or audit scrutiny.

A Medicare payment classification system for inpatient hospital stays that groups patients with similar diagnoses and resource usage into a single fixed payment amount. The hospital receives the DRG payment regardless of actual costs incurred, creating incentives for efficiency. DRGs are used for payment under Medicare Part A (inpatient) but not for outpatient services.

The computer-to-computer exchange of standard business documents in a standard electronic format between trading partners. In healthcare, EDI standards (HIPAA X12 transactions) include: 837P/I (claims submission), 835 (payment/remittance), 270/271 (eligibility inquiry/response), 276/277 (claim status inquiry), and 278 (prior authorization). EDI enables faster, more accurate claims processing than paper.

The process of confirming a patient's active insurance coverage, plan benefits, co-pay/deductible amounts, and coverage for specific services before the appointment. Real-time eligibility can be checked via EDI 270/271 transactions. Verifying eligibility before every visit prevents claim denials due to inactive coverage, wrong subscriber ID, or plan changes — the source of 23% of all denials.

A subset of CPT codes (99202–99499) used to bill for physician visits, consultations, and cognitive services. Since the 2021 AMA E/M revisions, office visit levels (99202–99215) are determined by medical decision making (MDM) or total time. Correct E/M coding is critical — undercoding costs revenue, while overcoding creates audit risk.

A statement sent from an insurance company to a patient and/or provider after a claim is processed. It details: the service date and description, amount billed, allowed amount, any adjustments, the amount paid by the plan, and the patient's remaining responsibility. An EOB is not a bill — it is an explanation of how the claim was adjudicated. The electronic version sent to providers is called an ERA.

The electronic equivalent of an EOB sent from insurance companies directly to provider billing systems. ERAs are transmitted as EDI 835 transactions and enable automated payment posting. ERA adoption eliminates manual payment entry, reduces posting errors, and speeds up the reconciliation process. Providers must enroll with each payer to receive ERAs instead of paper checks and EOBs.

A federally required Medicaid benefit for children under age 21 that covers comprehensive preventive and curative health services. EPSDT ensures children receive necessary services even if the state Medicaid plan does not otherwise cover that service. Providers billing Medicaid for pediatric care should be familiar with EPSDT coverage rules.

A complete listing of maximum fees that a payer will allow for specific services. Medicare publishes an annual Physician Fee Schedule (PFS) with national and geographically adjusted rates for every CPT code. Providers negotiate contracted fee schedules with commercial payers. Billing above your fee schedule is common practice; collecting above the allowed amount is prohibited for in-network providers.

The percentage of claims accepted and paid by payers on the very first submission without requiring corrections, resubmission, or appeal. Also called Clean Claim Rate. Industry average is approximately 85%. Best-in-class billing operations achieve 97–99%. Improving first-pass rate directly reduces administrative costs and accelerates cash flow.

Fraud is the intentional submission of false claims for services not rendered or not covered, such as upcoding or billing for phantom patients. Abuse involves billing practices that are inconsistent with sound medical practices and result in unnecessary costs, such as excessive ordering of unnecessary tests. The False Claims Act imposes treble damages and per-claim civil penalties on fraudulent billing.

A Medicare policy that bundles pre-operative, intra-operative, and post-operative care for surgical procedures into a single payment. The global period is 0, 10, or 90 days depending on the procedure. During the global period, routine follow-up visits are not separately billable. Services that are not part of the global package (e.g., a new and unrelated problem) may be billed separately with Modifier 24.

The person financially responsible for paying a patient's medical bills. Often the patient themselves, but may be a parent or guardian for minor children, or a spouse. The guarantor is the entity responsible for any patient responsibility balance remaining after insurance pays. Patient statements are sent to the guarantor.

A two-level coding system used to identify products, supplies, and services for billing purposes. Level I HCPCS is identical to CPT codes. Level II HCPCS codes (starting with a letter followed by 4 digits) cover products, supplies, and services not included in CPT, such as durable medical equipment (DME), ambulance services, drugs, vaccines (J-codes), and orthotics/prosthetics.

A 1996 federal law establishing national standards for protecting the privacy and security of patient health information. HIPAA's Privacy Rule governs how PHI may be used and disclosed. The Security Rule sets standards for electronic PHI safeguards. The Transactions Rule mandates standard electronic formats for healthcare data exchange. Violations can result in civil penalties up to $1.9 million per violation category per year.

A type of managed care health plan that requires members to select a primary care physician (PCP) and obtain referrals for specialist care. HMOs generally have lower premiums and out-of-pocket costs but restrict coverage to in-network providers. Billing HMO patients requires verifying PCP assignment, referral requirements, and capitation arrangements where applicable.

The standardized diagnostic coding system used in the United States since October 1, 2015 to classify diagnoses, symptoms, and reasons for healthcare encounters. ICD-10-CM (Clinical Modification) is used for outpatient/physician billing. ICD-10-PCS (Procedure Coding System) is used by hospitals for inpatient procedure coding. ICD-10-CM has ~70,000 codes offering far greater specificity than ICD-9.

A Medicare billing provision allowing non-physician practitioners (NPPs) to bill under the supervising physician's NPI at 100% of the physician fee schedule (rather than 85% for independent NPP billing), provided specific supervision requirements are met: the physician must see the patient for the initial visit, the NPP must provide subsequent visits for the same condition, and the physician must be physically present in the office suite during the service.

A healthcare provider who has contracted with a specific insurance plan to provide services at pre-negotiated rates. In-network providers accept the payer's allowed amount as payment in full (minus patient cost-sharing) and cannot balance bill patients for the difference. Patients typically pay lower out-of-pocket costs when seeing in-network providers.

A subset of Level II HCPCS codes (J0000–J9999) used to bill for injectable and infusible drugs administered in a medical setting. J-codes are specific to the drug, formulation, and quantity administered. Examples include J0171 (epinephrine), J0696 (ceftriaxone), and J9305 (pembrolizumab). J-codes must be paired with the appropriate administration CPT code (96365–96379 for infusions, 96372 for injections).

A HCPCS modifier required by Medicare for certain therapy services (physical therapy, occupational therapy, speech-language pathology) to indicate that the services are medically necessary and that the provider has documentation in the medical record to support that necessity. The KX modifier is required when therapy charges exceed the Medicare therapy cap threshold.

A Medicare Administrative Contractor (MAC)-issued policy that defines when a specific service or item is covered (i.e., medically necessary) in a particular geographic jurisdiction. LCDs include covered diagnoses (ICD-10 codes), documentation requirements, and frequency limitations. Claims that do not meet LCD criteria are denied for medical necessity.

Ensuring that claims for Medicare services comply with applicable Local Coverage Determinations and National Coverage Determinations by linking appropriate ICD-10 diagnosis codes to the procedure codes billed and meeting documentation requirements. Non-compliance results in medical necessity denials that are difficult to appeal.

A private company contracted by CMS to process Medicare fee-for-service claims in a specific geographic jurisdiction. MACs handle claim processing, enrollment, medical review, and audit activities for both Part A (institutional) and Part B (professional) Medicare claims. Examples include Novitas Solutions, CGS Administrators, and Palmetto GBA.

The criterion used by payers to determine whether a service is appropriate and should be reimbursed. A service is medically necessary when it is consistent with the diagnosis, meets accepted standards of medical practice, and is not primarily for the patient's or provider's convenience. Payers use LCD/NCD policies to define medical necessity criteria for specific services.

A joint federal and state program that provides health coverage to eligible low-income individuals, including children, pregnant women, elderly adults, and people with disabilities. Each state administers its own Medicaid program within federal guidelines, resulting in significant variation in covered services, rates, and billing requirements by state.

The federal health insurance program primarily providing coverage for Americans age 65 and older, and certain younger people with disabilities or end-stage renal disease. Medicare has four parts: Part A (hospital insurance), Part B (medical insurance/outpatient), Part C (Medicare Advantage — private plans), and Part D (prescription drug coverage).

A two-character alphanumeric code appended to a CPT or HCPCS procedure code to indicate that a service was altered in some way without changing its definition. Common modifiers: 25 (separate E/M on same day as procedure), 50 (bilateral), 51 (multiple procedures), 59 (distinct procedural service), GT (telehealth), and 26/TC (professional/technical component). Incorrect modifier use is the leading cause of claim denials.

Federal rules governing when Medicare is the secondary — rather than primary — payer for a beneficiary's healthcare. When a Medicare patient has other primary insurance (employer group health, auto, workers' comp, liability), Medicare must be billed secondary. Failing to identify MSP situations and billing Medicare primary results in overpayments that must be repaid.

CMS-established claim edits that define the maximum number of units of a service that would reasonably be provided to a patient on a single date of service. Claims exceeding MUE limits are automatically denied. MUEs are based on anatomical considerations, code descriptors, and clinical standards. Some MUEs can be overridden with modifier 59 or X modifiers when services truly exceeded the edit.

CMS-developed coding edits that prevent improper payment when certain codes are billed together. NCCI edits include Procedure-to-Procedure (PTP) edits (mutually exclusive code pairs) and Medically Unlikely Edits (MUEs). Some edits can be overridden with appropriate modifiers; others cannot. Violating NCCI edits without a valid modifier constitutes improper unbundling.

A Medicare policy issued by CMS that establishes nationwide coverage criteria for specific services or items. Unlike LCDs (which vary by geography), NCDs apply uniformly across all Medicare jurisdictions. NCDs define covered indications, non-covered indications, and documentation requirements. Examples include NCDs for bariatric surgery, CPAP for sleep apnea, and cochlear implants.

A key performance indicator measuring the percentage of expected reimbursement that was actually collected. Calculated as: (Payments Collected ÷ (Total Charges – Contractual Adjustments)) × 100. Best-in-class: 99%+. Below 95% indicates significant revenue leakage. Differs from gross collection rate, which includes uncollectable amounts.

A unique 10-digit identification number assigned to every healthcare provider by CMS for use in all HIPAA standard transactions. Individual providers hold a Type 1 NPI; organizations and groups hold a Type 2 NPI. The NPI replaced legacy provider numbers (UPIN, PIN) and must appear on all claims submitted to Medicare, Medicaid, and commercial payers.

The U.S. Department of Health & Human Services division responsible for identifying and combating fraud, waste, and abuse in Medicare, Medicaid, and other federal health programs. The OIG publishes an annual Work Plan listing its audit and investigation priorities, which billing and compliance departments use to identify areas of risk. The OIG can impose civil monetary penalties, exclusion from federal programs, and criminal referrals.

A healthcare provider who has not contracted with a patient's insurance plan. Out-of-network services typically result in higher patient cost-sharing or no coverage. The No Surprises Act (2022) limits when providers can balance bill patients for out-of-network services at in-network facilities, particularly in emergency and certain non-emergency situations.

The maximum amount a patient will pay for covered services in a plan year, including deductibles, co-pays, and coinsurance. Once reached, the insurance plan pays 100% of covered in-network services for the remainder of the plan year. ACA plans set annual out-of-pocket maximums (2026: $9,200 individual, $18,400 family for marketplace plans).

The amount a patient owes for healthcare services after insurance has processed the claim, including deductibles, copays, coinsurance, and non-covered charges. Communicating estimated patient responsibility before the visit improves collection rates. Practices that collect patient responsibility at the time of service significantly reduce the cost of collecting balances after the fact.

Any entity that pays for healthcare services on behalf of a patient. Includes: commercial insurance companies (Aetna, BCBS, Cigna, UHC), government programs (Medicare, Medicaid, TRICARE, VA), managed care organizations, and self-pay patients. Each payer has its own claim submission requirements, fee schedules, and medical policies.

The administrative process of registering a provider with an insurance company's network so they can submit claims and receive reimbursement. Payer enrollment is distinct from credentialing: credentialing verifies qualifications, while enrollment establishes the billing relationship. Enrollment timelines range from 30 days (Medicare) to 90–120 days (commercial payers).

Any individually identifiable health information held or transmitted by a covered entity or business associate that relates to an individual's physical or mental health, healthcare services received, or payment for those services. PHI includes names, dates, addresses, phone numbers, SSNs, medical record numbers, and almost any information that could identify a patient. PHI must be protected under HIPAA.

A two-digit code on the CMS-1500 claim form indicating the location where services were rendered. Common codes: 11 (office), 19 (off-campus outpatient hospital), 21 (inpatient hospital), 22 (on-campus outpatient hospital), 23 (emergency room), 31 (skilled nursing facility). The POS code affects payment rates — Medicare pays less for services in hospital outpatient settings than in the office.

A type of health insurance plan that contracts with a network of preferred providers at discounted rates. Unlike HMOs, PPOs allow members to see out-of-network providers (at higher cost) without requiring a referral. PPO members have more flexibility in provider choice but typically pay higher premiums than HMO enrollees.

The amount paid (usually monthly) to an insurance company to maintain health coverage, regardless of whether any medical services are used. Premiums may be paid by employers, employees, individuals, or government programs. Failure to pay premiums results in loss of coverage, which affects claim payment for dates of service during the lapse.

A requirement by an insurance company that a provider obtain approval before scheduling or performing a specific service, procedure, or prescribing certain medications. PA requirements are payer- and plan-specific. Even if PA is approved, it must match the exact service, dates, facility, and rendering provider. Retroactive PA is rarely granted; services performed without required PA are frequently denied.

A Medicare savings program that helps people with limited income and resources pay for Medicare costs. QMB-eligible beneficiaries receive assistance with Medicare premiums, deductibles, and cost-sharing. Providers who accept Medicare are required to accept QMB as payment in full for Medicare-covered services and cannot bill QMB patients for any cost-sharing amounts.

The end-to-end financial process healthcare organizations use to manage all clinical and administrative functions associated with claims revenue, from patient scheduling and registration through final payment collection. The RCM cycle includes: eligibility verification, charge capture, coding, claims submission, payment posting, denial management, and patient collections.

A claim returned to the provider before adjudication because it contained technical errors that prevented processing. Common rejection reasons: invalid NPI, incorrect payer ID, missing required fields, improper date formats, or duplicate claim submission. Rejections are not adjudicated — they must be corrected and resubmitted. Rejections are different from denials.

A document from a payer explaining payment, denial, or adjustment decisions for submitted claims. Paper versions are called EOBs (Explanations of Benefits); electronic versions are called ERAs (Electronic Remittance Advices), transmitted as EDI 835 transactions. Remittance advice is used for payment posting, denial identification, and contractual adjustment reconciliation.

A technology-enabled healthcare delivery method that allows providers to monitor patients outside of clinical settings using digital devices that transmit physiologic data. RPM billing uses CPT codes 99453 (setup), 99454 (device supply, ≥16 days of data), 99457 (20 minutes of monitoring/care management/month), and 99458 (each additional 20 minutes). Medicare reimburses RPM for managing chronic conditions.

The automated or manual process of reviewing claims for errors, missing information, coding conflicts, and compliance issues before submission to reduce rejections and denials. A robust claim scrubbing engine validates demographics, coding accuracy (NCCI, MUE), medical necessity linkage, prior authorization presence, timely filing status, and payer-specific rules. High-quality scrubbing is the primary driver of first-pass acceptance rates.

Patients who pay for healthcare services out-of-pocket without insurance coverage, or who are uninsured. Also called cash-pay patients. Self-pay patients typically receive discounted rates (e.g., Medicare-equivalent rates or a percentage of billed charges). Best practice is to collect a deposit at the time of service and establish a payment plan for the remainder.

A detailed invoice or encounter form generated by a provider after a patient visit, listing the services rendered with corresponding CPT codes, the diagnoses with ICD-10 codes, the rendering provider, and the fee for each service. Superbills serve as the source document for claim creation. Incomplete or inaccurate superbills are a major cause of missed charges.

A 10-digit alphanumeric code that classifies a provider's type, classification, and specialization for administrative and financial transactions. Taxonomy codes are used on claims and enrollment applications to identify the provider's specialty. Using the wrong taxonomy code on a claim can result in denial or incorrect fee schedule application, particularly for Medicare.

A nine-digit number issued by the IRS used to identify a business or individual for tax purposes. In healthcare billing, the TIN (also called EIN for Employer Identification Number) identifies the practice entity that receives payment. The billing entity's TIN on a claim must match what is on file with the payer during credentialing and enrollment.

The deadline by which a claim must be submitted to an insurance company after services are rendered or after a primary payer has processed the claim (for secondary billing). Timely filing limits vary by payer: Medicare requires 12 months from DOS; Medicaid varies by state (30 days to 24 months); commercial payers typically require 90–180 days. Timely filing denials are generally not appealable.

The healthcare program serving active duty service members, National Guard and Reserve members, retirees, and their families worldwide. TRICARE is managed by the Defense Health Agency. Providers must be TRICARE-authorized to bill TRICARE patients. There are several TRICARE plan types (Prime, Select, for Life) with different cost-sharing and provider requirements.

The standard claim form used by hospitals, skilled nursing facilities, and other institutional providers to bill insurance companies for inpatient and outpatient facility services. The UB-04 uses revenue codes, occurrence codes, and type-of-bill codes in addition to ICD-10 and CPT/HCPCS codes. The electronic equivalent is the 837I (institutional) EDI transaction.

The fraudulent practice of billing for a more extensive or expensive service than was actually provided or documented. Examples include billing a Level 5 E/M visit when documentation only supports a Level 3, or billing a more complex surgical code than what was performed. Upcoding is a violation of the False Claims Act and can result in criminal prosecution, exclusion, and large financial penalties.

A healthcare delivery model in which providers are reimbursed based on patient health outcomes and quality metrics rather than the volume of services delivered. Contrasted with fee-for-service reimbursement. Value-based payment arrangements include Medicare Shared Savings Program ACOs, bundled payment models, and pay-for-performance programs. Billing and coding in value-based models requires accurate chronic condition capture (HCC coding).

State-regulated insurance programs that provide wage replacement and medical benefits to employees injured during employment. Workers' compensation claims have separate billing rules: providers must use state-specific forms (not CMS-1500 in some states), submit to the employer's insurance carrier rather than health insurance, and obtain an authorization number from the carrier before treatment in most states.

An amount permanently removed from a patient's account balance that will not be collected. Types of write-offs include: contractual adjustments (difference between billed charge and payer allowed amount — expected and appropriate), bad debt write-offs (uncollectible balances after collection efforts), charity care (financial assistance for low-income patients), and small balance write-offs (amounts below a threshold not worth pursuing).

A set of HCPCS modifiers introduced by CMS in 2015 as more specific alternatives to Modifier 59 (Distinct Procedural Service). XE = Separate Encounter; XP = Separate Practitioner; XS = Separate Structure (distinct organ or structure); XU = Unusual Non-Overlapping Service. Using the appropriate X modifier rather than 59 provides additional specificity and reduces audit risk.

ICD-10-CM Z-codes that capture social determinants of health (SDOH) — non-medical factors that influence a patient's health outcomes. Examples include Z59.0 (homelessness), Z60.2 (living alone), Z63.4 (disappearance or death of family member), and Z77.010 (contact with and exposure to arsenic). CMS increasingly emphasizes SDOH coding for value-based care quality reporting and population health management.