Medical Billing Terms M: Billing Modifiers 25, 59, 93, GT, FQ and HO
Billing modifiers are two-character codes added to a procedure code to give payers more detail about how a service was delivered. This page defines the modifier and modifiers 25, 59, 93, AH, AJ, FQ, GT, HN, HO and HP, plus MIPS, MLN and MFA. Each entry gives a plain definition, why it matters, an example, and an official source. MCM South Medical Billing Service, LLC works only in mental and behavioral health billing.
On this page (21 terms)
- Midpoint Rule (Timed Codes)
- Minimum Necessary
- Minor Consent Law
- MIPS (Merit-Based Incentive Payment System)
- MLN (Medicare Learning Network)
- Mobile Crisis Services
- Modified Adjusted Gross Income (MAGI)
- Modifier
- Modifier 25
- Modifier 59
- Modifier 93
- Modifier AH
- Modifier AJ
- Modifier FQ
- Modifier GT
- Modifier HN
- Modifier HO
- Modifier HP
- Modio Health
- Molina Healthcare
- Multi-Factor Authentication (MFA)
How to use these Billing Modifiers definitions
Use this page as a quick reference for Billing Modifiers, from Midpoint Rule to Multi-Factor Authentication. Each entry gives a plain definition, why it matters to a mental health practice, and an official source. When a rule changes by payer or state, the entry says so, so confirm Billing Modifiers details with the payer before you bill.
Checklist: put the billing modifiers definitions to work
- Check the billing modifiers entries above before you send a claim that depends on them.
- Share this billing modifiers page with front-desk and billing staff so everyone works from the same definitions.
- When a payer letter mentions billing modifiers, find the matching entry and note the date you checked it.
- Keep your billing modifiers notes next to your payer contracts, because a contract can define a term differently.
- Ask the payer to confirm in writing how it applies billing modifiers before you change a workflow.
- Train new staff on billing modifiers first, then move on to the rest of the glossary.
- Log any billing modifiers question that comes up twice, then add the answer to your billing procedures.
- Use the source links under the billing modifiers entries to confirm the current rule.
- Print the billing modifiers entries you use most and keep them at the billing desk.
Midpoint Rule (Timed Codes)
Also called midpoint rule; time rule CPT; when a unit of time is met
- Definition
- The midpoint rule is a CPT convention that a unit of time is attained when the midpoint is passed. It underlies why psychotherapy minute ranges start at 16, 38, and 53 minutes.
- Why it matters
- Payers apply time rules in different ways, so always use the payer's stated range. Do not round up. Record exact start and stop times.
- Illustrative example
- A therapist's 37-minute session is billed 90832, not 90834, because it did not reach 38 minutes.
Related termsPsychotherapy Time RangesCPT 90832CPT 90834Documentation
Reference sourceAmerican Medical Association (AMA)checked 10/9/26
CategoriesClaims Processing
Minimum Necessary
Also called minimum necessary standard
- Definition
- A HIPAA standard that requires limiting the use and disclosure of PHI to the minimum needed for the purpose, with exceptions such as treatment.
- Why it matters
- Applies to what a biller shares with payers and vendors.
- Illustrative example
- A biller sends only the notes a payer requested.
Related termsHIPAA Privacy RuleProtected Health Information (PHI)Guide: HIPAA for billing
Reference sourceHHS (U.S. Department of Health and Human Services)HHS Office for Civil Rights (OCR)checked 10/9/26
CategoriesAudits & Compliance
Minor Consent Law
Also called minor consent statute; consent by minors; minors' right to consent
- Definition
- A minor consent law is a state statute that lets a person under the age of majority consent to certain health services without a parent's permission. Common examples cover outpatient mental health care, substance use treatment, and reproductive health care.
- Why it matters
- Each state writes its own rules for which services, what minimum age, what conditions, and whether a parent is told or must pay. The rules can conflict from state to state, so check the statute for the patient's state.
- Illustrative example
- A therapist checks the state's minor consent statute for outpatient mental health care before scheduling a 15-year-old who came alone.
Related termsAge of Majority (Healthcare)Emancipated MinorPersonal Representative (HIPAA)State MandateGuide: Minor consent billing
Reference sourceNational Center for Youth Law, Minor Consent Compendium 2024: ConnecticutHHS, HIPAA FAQ 516: disclosure to parents of a teenchecked 10/9/26
CategoriesAudits & ComplianceBehavioral Health Specific Terms
MIPS (Merit-Based Incentive Payment System)
Also called MIPS
- Definition
- A Medicare program that adjusts payment for eligible clinicians based on performance in quality, cost, improvement activities, and promoting interoperability.
- Why it matters
- Affects Medicare payment for clinicians above eligibility thresholds.
- Illustrative example
- A group reports MIPS quality measures.
Related termsMACRAQuality Payment Program (QPP)HEDIS
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS Quality Payment Programchecked 10/9/26
CategoriesValue-Based Care TerminologyQuality & Risk Adjustment Terms
MLN (Medicare Learning Network)
Also called MLN; Medicare Learning Network
- Definition
- A CMS education program with fact sheets, booklets, and articles for providers on Medicare billing and policy.
- Why it matters
- A reliable source for Medicare rules and definitions.
- Illustrative example
- A practice reads an MLN booklet on mental health services.
Related termsCMS (Centers for Medicare & Medicaid Services)Medicare
Reference sourceCMS Medicare Learning Network (MLN)checked 10/9/26
CategoriesMedicare & Medicaid Terms
Mobile Crisis Services
Also called mobile crisis; crisis response team; Medicaid mobile crisis
- Definition
- Mobile crisis services are crisis response services delivered in the community by a team that goes to the person, rather than requiring a visit to a facility. Some state Medicaid programs cover them.
- Why it matters
- Coverage, provider types, and codes vary by state. They link to 988 and to crisis codes.
- Illustrative example
- A state Medicaid program pays a provider for a mobile crisis visit to a patient's home.
Related terms988 Suicide and Crisis LifelineCrisis Psychotherapy (90839 / 90840)Medicaid HCPCS CodeMedicaidGuide: Crisis services billing
Reference sourceMedicaid.govSAMHSAchecked 10/9/26
CategoriesBehavioral Health Specific TermsMedicare & Medicaid Terms
Modified Adjusted Gross Income (MAGI)
Also called MAGI; Medicaid MAGI eligibility; MAGI-based Medicaid
- Definition
- Modified adjusted gross income is the income method that Medicaid and CHIP use to decide eligibility for many groups, such as children, parents, pregnant people, and adults in expansion states.
- Why it matters
- It explains how eligibility is figured for many adults and children. Household size and income rules matter, and states run their own programs.
- Illustrative example
- A family's Medicaid eligibility is checked using MAGI rules and the state's income limit.
Related termsMedicaid ExpansionMedicaidCHIP (Children's Health Insurance Program)Federal Poverty Level (FPL)
Reference sourceMedicaid.govCMS (Centers for Medicare & Medicaid Services)checked 10/9/26
Modifier
Also called CPT modifier; HCPCS modifier; billing modifier
- Definition
- A two-character code appended to a procedure code to give more information, such as telehealth delivery, distinct services, or provider type.
- Why it matters
- Missing or wrong modifiers cause denials or wrong payment.
- Illustrative example
- A telehealth session is billed with modifier 95 when the payer requires it.
Related termsTelehealth Modifier 95Modifier 25Modifier 59Modifier HO
Reference sourceAmerican Medical Association (AMA)CMS HCPCSchecked 10/9/26
CategoriesClaims Processing
Modifier 25
Also called 25 modifier; significant separately identifiable E/M
- Definition
- A modifier appended to an E/M code to show it was significant and separately identifiable from another service performed the same day, such as a procedure.
- Why it matters
- Used by psychiatrists when an E/M and another procedure are billed the same day.
- Illustrative example
- A psychiatrist bills an E/M with modifier 25 alongside a separately reportable procedure.
Related termsModifierE/M CodeNCCI Edits
Reference sourceAmerican Medical Association (AMA)CMS National Correct Coding Initiative (NCCI)checked 10/9/26
Modifier 59
Also called 59 modifier; distinct procedural service; X modifiers
- Definition
- A modifier indicating a procedure is distinct from another performed the same day, used to bypass certain bundling edits. Medicare also has more specific X{EPSU} modifiers.
- Why it matters
- Misuse is an audit target; it should be used only when documentation supports it.
- Illustrative example
- A payer edit bundles two codes and modifier 59 is used only if documentation supports separate services.
Related termsNCCI EditsModifierAuditGuide: NCCI edits
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS National Correct Coding Initiative (NCCI)checked 10/9/26
CategoriesClaims Processing
Modifier 93
Also called 93 modifier; synchronous audio-only
- Definition
- A modifier indicating a service delivered through real-time audio-only telecommunications.
- Why it matters
- Payers differ on whether and how they cover audio-only.
- Illustrative example
- A payer requires modifier 93 for phone sessions.
Related termsTelehealth Modifier 95Modifier FQAudio-Only Telehealth
Reference sourceAmerican Medical Association (AMA)checked 10/9/26
CategoriesTelehealth TermsClaims Processing
Modifier AH
Also called AH modifier; clinical psychologist modifier
- Definition
- A HCPCS modifier Medicare has used to identify services of a clinical psychologist.
- Why it matters
- Some payers require provider-type modifiers on claims.
- Illustrative example
- A clinical psychologist adds AH where required.
Related termsModifierModifier AJ
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
Modifier AJ
Also called AJ modifier; clinical social worker modifier
- Definition
- A HCPCS modifier Medicare has used to identify services of a clinical social worker.
- Why it matters
- Provider-type modifiers can affect payment and processing.
- Illustrative example
- A licensed clinical social worker adds AJ where required.
Related termsModifierModifier AH
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
Modifier FQ
Also called FQ modifier; Medicare audio-only mental health telehealth modifier
- Definition
- A modifier Medicare has used to identify mental health services furnished using audio-only communication.
- Why it matters
- Applies to Medicare audio-only rules, which have changed over time.
- Illustrative example
- A Medicare claim for an audio-only session carries FQ under current rules.
Related termsModifier 93Audio-Only Telehealth
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
Modifier GT
Also called GT modifier; via interactive audio and video telecommunications
- Definition
- A modifier some payers use to indicate services delivered by interactive audio and video.
- Why it matters
- Used by some payers instead of or in addition to modifier 95.
- Illustrative example
- A payer requires GT on telehealth claims.
Related termsTelehealth Modifier 95Modifier 93
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
CategoriesTelehealth TermsClaims Processing
Modifier HN
Also called HN modifier; bachelor's-level modifier
- Definition
- A HCPCS modifier that some payers use to indicate services delivered by a bachelor's-level clinician.
- Why it matters
- Used in state-specific rate tiers.
- Illustrative example
- A community program bills with modifier HN.
Related termsModifier HOModifier HPModifier
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
Modifier HO
Also called HO modifier; master's-level modifier
- Definition
- A HCPCS modifier that some Medicaid programs and payers use to indicate services delivered by a master's-level clinician.
- Why it matters
- Some state Medicaid programs require HO, HN, or HP to set rate levels by clinician degree.
- Illustrative example
- A state pays a different rate for services with modifier HO than with HP.
Related termsModifierModifier HPModifier HNMedicaid HCPCS Code
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
Modifier HP
Also called HP modifier; doctoral-level modifier
- Definition
- A HCPCS modifier that some payers use to indicate services delivered by a doctoral-level clinician.
- Why it matters
- Affects rate differentiation in some Medicaid programs.
- Illustrative example
- A psychologist's Medicaid claim carries modifier HP.
Related termsModifier HOModifier HNModifier
Reference sourceCMS (Centers for Medicare & Medicaid Services)CMS HCPCSchecked 10/9/26
Modio Health
Also called Modio; Modio credentialing software
- Definition
- A vendor of credentialing and provider enrollment software used by health care organizations. Naming a vendor here is not an endorsement or partnership.
- Why it matters
- Illustrates the category of credentialing platforms billing teams may encounter.
- Illustrative example
- An organization uses a credentialing platform to track licenses and payer applications.
Related termsCredentialing SoftwareCAQH ProView
Reference sourceModio Healthchecked 10/9/26
CategoriesCredentialing & EnrollmentEHR & Healthcare Technology Terms
Molina Healthcare
Also called Molina
- Definition
- A national managed care company focused on government-sponsored programs, including Medicaid and Medicare plans.
- Why it matters
- Has state-specific plans and rules.
- Illustrative example
- A provider contracts with Molina in a state.
Related termsMedicaid Managed Care Organization (MCO)
Reference sourceMolina Healthcarechecked 10/9/26
CategoriesBCBS, UHC & Commercial Payer TermsMedicare & Medicaid Terms
Multi-Factor Authentication (MFA)
Also called MFA; two-factor authentication; 2FA
- Definition
- A security method that requires two or more proofs of identity to sign in.
- Why it matters
- Commonly expected for systems containing PHI.
- Illustrative example
- A biller logs into a payer portal with a password and code.
Related termsHIPAA Security RuleAudit Trail
Reference sourceHHS (U.S. Department of Health and Human Services)HHS Office for Civil Rights (OCR)checked 10/9/26
CategoriesEHR & Healthcare Technology TermsAudits & Compliance
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Quick answer: Billing Modifiers
What is a billing modifier?
Modifier is a two-character code appended to a procedure code to give more information, such as telehealth delivery, distinct services, or provider type. Missing or wrong modifiers cause denials or wrong payment.
Frequently asked questions: Billing Modifiers
What is modifier 25?
Modifier 25 is a modifier appended to an E/M code to show it was significant and separately identifiable from another service performed the same day, such as a procedure. Used by psychiatrists when an E/M and another procedure are billed the same day.
What is modifier 93?
Modifier 93 is a modifier indicating a service delivered through real-time audio-only telecommunications. Payers differ on whether and how they cover audio-only.
What is modifier HO?
A HCPCS modifier that some Medicaid programs and payers use to indicate services delivered by a master's-level clinician. Some state Medicaid programs require HO, HN, or HP to set rate levels by clinician degree.
Related resources
Where MCM South works
MCM South serves psychotherapists and psychiatrists in ten states: Georgia, Massachusetts, Connecticut, Texas, Florida, New York, Colorado, Tennessee, North Carolina and Illinois.
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