| MACHINE | Class | |
| MACHINE IDENTIFIER | Attribute | |
| MACHINE IDENTIFIER | Data Element | |
| MACHINE TYPE | Attribute | |
| Main Menu | Supporting Information | |
| MAIN SPECIALTY | Class | |
| Main Specialty And Treatment Function Codes | Supporting Information | |
| MAIN SPECIALTY CATEGORY CODE FOR BED AVAILABILITY AND OCCUPANCY | Data Element | |
| MAIN SPECIALTY CATEGORY CODE FOR BED AVAILABILITY AND OCCUPANCY | Attribute | |
| MAIN SPECIALTY CODE | Data Element | |
| MAIN SPECIALTY CODE | Attribute | |
| MAIN SPECIALTY CODE (AUGMENTED CARE PERIOD) (retired) | Data Element | |
| MAIN SPECIALTY CODE (MENTAL HEALTH) | Data Element | |
| Maintenance | Supporting Information | |
| MALIGNANT ABNORMALITY | Class | To top |
| MANIFEST PSYCHOSIS DATE | Data Element | |
| Mantoux Test | Supporting Information | |
| MANTOUX TESTS PERFORMED TOTAL (TUBERCULOSIS) | Data Element | |
| MARITAL STATUS | Data Element | |
| MARKER LYMPH NODE RESULT | Data Element | |
| MARKER LYMPH NODE RESULT | Attribute | |
| MARKER RESPONSE STATUS | Data Element | |
| MARKER RESPONSE STATUS | Attribute | |
| MATERNAL HEP B STATUS | Attribute | |
| MATERNAL RUBELLA STATUS | Attribute | |
| Maternity and Childrens Data Sets Submission Requirements | Supporting Information | |
| Maternity Domiciliary Visit | Supporting Information | |
| Maternity Medical Service | Supporting Information | |
| MATERNITY MEDICAL SERVICE TYPE | Attribute | |
| MATERNITY VISIT CALL REASON | Attribute | To top |
| MAXIMUM WAIT FOR DAY CASE ADMISSION | Attribute | |
| MAXIMUM WAIT FOR ORDINARY ADMISSION | Attribute | |
| M CATEGORY (FINAL PRETREATMENT) | Data Element | |
| M CATEGORY (INTEGRATED STAGE) | Data Element | |
| M CATEGORY (PATHOLOGICAL) | Data Element | |
| M CATEGORY EXTENDED (PATHOLOGICAL) | Data Element | |
| MEASURED OBSERVATION VALUE | Attribute | |
| MEASURED PERSON OBSERVATION | Class | |
| MEASURED PERSON OBSERVATION TYPE | Class | |
| MEASURED PERSON OBSERVATION TYPE CODE | Attribute | |
| Measured Referral to Treatment Period | Supporting Information | |
| MEASUREMENT VALUE TYPE | Class | |
| MEASUREMENT VALUE TYPE CODE | Attribute | |
| Medical & Dental Practice Codes (retired) | Supporting Information | |
| MEDICAL AND DENTAL POST SPECIALTY GROUP | Attribute | To top |
| MEDICAL STAFF TYPE SEEING PATIENT | Data Element | |
| MEDICAL STAFF TYPE SEEING PATIENT | Attribute | |
| MENSTRUAL STATUS | Data Element | |
| MENSTRUAL STATUS | Attribute | |
| MENTAL CATEGORY | Data Element | |
| MENTAL CATEGORY | Attribute | |
| Mental Health | Supporting Information | |
| Mental Health Absence Without Leave | Supporting Information | |
| MENTAL HEALTH ACT 2007 MENTAL CATEGORY | Data Element | |
| MENTAL HEALTH ACT 2007 MENTAL CATEGORY | Attribute | |
| MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION | Class | |
| MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE | Data Element | |
| MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE | Attribute | |
| MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE (AT CENSUS DATE) | Data Element | |
| MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE (ON ADMISSION) | Data Element | To top |
| Mental Health Act Table | Supporting Information | |
| MENTAL HEALTH CARE AND LEGAL STATUS HISTORY (retired) | Data Element | |
| Mental Health Care Assessment Date | Supporting Information | |
| Mental Health Care Cluster | Supporting Information | |
| MENTAL HEALTH CARE CLUSTER | Class | |
| Mental Health Care Cluster Assignment Period | Supporting Information | |
| MENTAL HEALTH CARE CLUSTER CODE | Data Element | |
| MENTAL HEALTH CARE CLUSTER CODE | Attribute | |
| MENTAL HEALTH CARE CLUSTER END REASON | Attribute | |
| MENTAL HEALTH CARE CLUSTER END REASON | Data Element | |
| Mental Health Care Cluster Super Class | Supporting Information | |
| MENTAL HEALTH CARE CLUSTER SUPER CLASS CODE | Attribute | |
| MENTAL HEALTH CARE CLUSTER SUPER CLASS CODE | Data Element | |
| Mental Health Care Coordinator Assignment | Supporting Information | |
| Mental Health Care Professional Episode (Acute Home-Based) | Supporting Information | To top |
| Mental Health Care Spell | Supporting Information | |
| MENTAL HEALTH CARE SPELL END CODE (retired) | Data Element | |
| MENTAL HEALTH CARE SPELL END CODE (retired) | Attribute | |
| Mental Health Care Spell Suspension | Supporting Information | |
| Mental Health Care Team Member | Supporting Information | |
| MENTAL HEALTH CARE TEAM TYPE (AT END OF REPORTING PERIOD) (retired) | Data Element | |
| Mental Health Care Without Patient Consent | Supporting Information | |
| Mental Health Clustering Tool | Supporting Information | |
| MENTAL HEALTH CLUSTERING TOOL ASSESSMENT REASON | Data Element | |
| MENTAL HEALTH CLUSTERING TOOL ASSESSMENT REASON | Attribute | |
| Mental Health Crisis Plan | Supporting Information | |
| MENTAL HEALTH CRISIS PLAN CREATION DATE | Data Element | |
| MENTAL HEALTH CRISIS PLAN LAST UPDATED DATE | Data Element | |
| MENTAL HEALTH DATA SET TYPE LIST (retired) | Supporting Information | |
| Mental Health Delayed Discharge Period | Supporting Information | To top |
| MENTAL HEALTH DELAYED DISCHARGE REASON | Attribute | |
| MENTAL HEALTH DELAYED DISCHARGE REASON | Data Element | |
| Mental Health Leave Of Absence | Supporting Information | |
| Mental Health Minimum Data Set (retired) | Data Set | |
| Mental Health Minimum Data Set (Version 4-0) | Data Set | |
| Mental Health Minimum Data Set Message Schema Versions (retired) | Supporting Information | |
| Mental Health Minimum Data Set Overview | Supporting Information | |
| Mental Health NHS Day Care Episode | Supporting Information | |
| Mental Health Nursing | Supporting Information | |
| Mental Health Responsible Clinician | Supporting Information | |
| Mental Health Responsible Clinician Assignment | Supporting Information | |
| MENTAL HEALTH RESPONSIBLE CLINICIAN PROFESSION | Data Element | |
| MENTAL HEALTH RESPONSIBLE CLINICIAN PROFESSION | Attribute | |
| Messages Introduction (retired) | Supporting Information | |
| Messages Menu (retired) | Supporting Information | To top |
| META ACTIVITY | Class | |
| META ACTIVITY IDENTIFIER | Attribute | |
| META ACTIVITY QUALIFIER | Class | |
| META ACTIVITY QUALIFIER IDENTIFIER | Attribute | |
| META ACTIVITY SITE | Class | |
| META ACTIVITY STATE ATTAINED DATE | Attribute | |
| META ACTIVITY STATE ATTAINED TIME | Attribute | |
| META ACTIVITY STATE ATTAINED TYPE | Attribute | |
| META AGENT | Class | |
| META AGENT IDENTIFIER | Attribute | |
| Meta Attribute Definitions Introduction | Supporting Information | |
| METABOLIC SCREENING | Attribute | |
| META CARE ACTIVITY | Class | |
| META CARE ACTIVITY CONTEXT | Class | |
| META CARE ACTIVITY DIRECT | Class | To top |
| META CARE ACTIVITY IN CONTEXT | Class | |
| META CARE PATHWAY USE | Class | |
| META CARE PROFESSIONAL | Class | |
| META CARER FOR PERSON | Class | |
| META CARE SPELL | Class | |
| META CARE SPELL IDENTIFIER | Attribute | |
| META CHANGE ACTIVITY STATE | Class | |
| Meta Class Definitions Introduction | Supporting Information | |
| META CONTRACT IDENTIFIER | Attribute | |
| META CONTRACTOR | Class | |
| META CONTRACTUAL RELATIONSHIP | Class | |
| Metadata Files | Supporting Information | |
| Meta Diagrams Introduction | Supporting Information | |
| META DIRECT ACTIVITY QUALIFIER | Class | |
| META DIRECT PERSON PROPERTY QUALIFIER | Class | To top |
| META EMPLOYEE | Class | |
| META HEALTH AND SOCIAL CARE ISSUE | Class | |
| META INDIRECT ACTIVITY QUALIFIER | Class | |
| META INDIRECT PERSON PROPERTY QUALIFIER | Class | |
| Meta Model Attributes Menu | Supporting Information | |
| Meta Model Class Menu | Supporting Information | |
| Meta Model Diagrams Menu | Supporting Information | |
| Meta Model Introduction | Supporting Information | |
| Meta Model Menu | Supporting Information | |
| META ORGANISATION | Class | |
| META ORGANISATION IDENTIFIER | Attribute | |
| META ORGANISATION SITE | Class | |
| META ORGANISATION SITE IDENTIFIER | Attribute | |
| META ORGANISATION STRUCTURE | Class | |
| META ORGANISATION TYPE | Attribute | To top |
| META PATIENT | Class | |
| META PERSON | Class | |
| META PERSON IDENTIFIER | Attribute | |
| META PERSON OBSERVATION | Class | |
| META PERSON PROPERTY | Class | |
| META PERSON PROPERTY IDENTIFIER | Attribute | |
| META PERSON PROPERTY QUALIFIER | Class | |
| META PERSON PROPERTY QUALIFIER IDENTIFIER | Attribute | |
| META PERSON RELATIONSHIP | Class | |
| META PERSON ROLE IN ORGANISATION | Class | |
| META PLACE | Class | |
| META POST | Class | |
| META POST IDENTIFIER | Attribute | |
| META POST TYPE | Attribute | |
| META RESOURCE HELD | Class | To top |
| META RESOURCE USAGE | Class | |
| META ROLE IN ACTIVITY | Class | |
| META SERVICE OFFERED | Class | |
| META SERVICE OFFERED TYPE | Attribute | |
| META SESSION | Class | |
| META SESSION START TIME | Attribute | |
| METASTATIC SITE | Data Element | |
| METASTATIC SITE | Attribute | |
| METASTATIC STATUS | Attribute | |
| METASTATIC STATUS | Data Element | |
| META TIME SLOT | Class | |
| Metropolitan County | Supporting Information | |
| Metropolitan District | Supporting Information | |
| MHCS SUSPENSION REASON (AT END OF REPORTING PERIOD) (retired) | Data Element | |
| MHC WITHOUT PATIENT CONSENT IN REPORTING PERIOD (retired) | Data Element | To top |
| MHMDS CONTROL NUMBER (retired) | Data Element | |
| MHMDS DATE CREATED (retired) | Data Element | |
| MHMDS DESTINATION IDENTIFICATION (retired) | Data Element | |
| MHMDS HEADER RECORD IDENTIFIER (retired) | Data Element | |
| MHMDS INTERFACE GATEWAY SERVICE TRANSLATION REFERENCE (retired) | Data Element | |
| MHMDS LOCAL PATIENT IDENTIFIER | Data Element | |
| MHMDS RECORD COUNT (retired) | Data Element | |
| MHMDS RECORD IDENTIFIER (retired) | Data Element | |
| MHMDS RECORD NUMBER (retired) | Data Element | |
| MHMDS SOURCE IDENTIFICATION (retired) | Data Element | |
| MHMDS TEST INDICATOR (retired) | Data Element | |
| MHMDS TIME CREATED (retired) | Data Element | |
| MHMDS TRAILER RECORD IDENTIFIER (retired) | Data Element | |
| MHMDS TRANSLATION REFERENCE (retired) | Data Element | |
| Middle Layer Super Output Area | Supporting Information | To top |
| MIDWIFE | Class | |
| Midwife Clinic | Supporting Information | |
| Midwife Episode | Supporting Information | |
| MIDWIFE EPISODE END REASON | Attribute | |
| MIDWIFERY ADMISSION RIGHT | Attribute | |
| MINIMALLY INVASIVE SURGERY INDICATOR | Data Element | |
| MINIMALLY INVASIVE SURGERY INDICATOR | Attribute | |
| Minor Surgery Procedure | Supporting Information | |
| MINOR SURGERY TYPE | Attribute | |
| Miscarriage Date | Supporting Information | |
| Miscellaneous (retired) | Supporting Information | |
| Mixed-Sex Accommodation Data Set | Data Set | |
| Mixed-Sex Accommodation Data Set Overview | Supporting Information | |
| Model Cross-References (retired) | Supporting Information | |
| MORBIDITY CODE | Attribute | To top |
| MORBIDITY CODE (CANCER SURGERY) | Data Element | |
| MORBIDITY CODE (CHEMOTHERAPY) | Data Element | |
| MORBIDITY CODE (COMBINATION) | Data Element | |
| MORBIDITY CODE (RADIOTHERAPY) | Data Element | |
| MORPHOLOGY (ICD-O AT START SYSTEMIC ANTI-CANCER THERAPY) | Data Element | |
| Multi-Bed Bay | Supporting Information | |
| MULTIDISCIPLINARY TEAM DISCUSSION DATE (CANCER) | Data Element | |
| MULTIDISCIPLINARY TEAM DISCUSSION DATE FOR CANCER | Attribute | |
| MULTIDISCIPLINARY TEAM DISCUSSION INDICATOR | Data Element | |
| Multidisciplinary Team Meeting | Supporting Information | |
| Mutually Exclusive Relationships | Supporting Information | |
| Mutually Exclusive Relationships - Reduced Arc | Supporting Information | |