Z51.81
BillableEncounter for therapeutic drug level monitoring
Encounter for therapeutic drug level monitoring
Coding Notes
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Excludes 2
Conditions not included here, but the patient may have both
Code Also
A second code may be required; sequencing depends on circumstances
- condition requiring care
- •any long-term (current) drug therapyZ79
Related Codes(1)
Also Known As / Clinical Terms(315)
SNOMED CT
- Ineffective drug action58848006
- Lack of drug action58848006
- Lack of drug effect58848006
- Drug action increased95899007
- Drug effect increased95899007
- Drug action decreased95900002
- Drug effect decreased95900002
- Drug action prolonged95901003
- Drug effect prolonged95901003
- Drug action shortened95902005
- Drug effect shortened95902005
- Drug action reversal95913008
- Drug effect reversal95913008
- Effects of immunotherapy109954009
- Therapeutic action of medication110280000
- Therapeutic drug action110280000
- Therapeutic drug effect110280000
- Phenobarbital level therapeutic166938002
- Phenobarbitone level therapeutic166938002
- Phenobarbital level low166939005
- Phenobarbitone level below therapeutic range166939005
- Phenobarbitone level low166939005
- Phenobarbital level high166940007
- Phenobarbitone level above therapeutic range166940007
- Phenobarbitone level high166940007
- Phenytoin level below reference range166942004
- Phenytoin level low166942004
- Phenytoin level therapeutic166943009
- Phenytoin level above therapeutic range166944003
- Phenytoin level high166944003
- Carbamazepine level therapeutic166950008
- Carbamazepine level below reference range166951007
- Carbamazepine level low166951007
- Carbamazepine level above reference range166952000
- Carbamazepine level high166952000
- Lithium level therapeutic166956002
- Lithium level below therapeutic range166958001
- Lithium level low166958001
- Digoxin level therapeutic166960004
- Digoxin level below therapeutic range166961000
- Digoxin level low166961000
- Digoxin level above therapeutic range166963002
- Digoxin level high166963002
- Intermittent drugs used more170611001
- Inhaler technique - poor170626004
- Bronchodilators used more than once daily170629006
- Bronchodilators used a maximum of once daily170630001
- Pre-treatment uric acid level170734001
- Hormone replacement monitoring check done185917005
- PEM completed185927004
- Prescription event monitoring completed185927004
- Prescription-event monitoring (PEM) completed185927004
- Gout monitoring status243859006
- Warfarin monitoring status243873002
- Bronchodilators used once daily274411003
- Phenothiazine injection - monitor275916009
- Asthma monitoring status308501009
- Hormone replacement monitoring status308534006
- Prescription event monitoring status309035009
- Aminophylline level365730009
- Aminophylline level - finding365730009
- Finding of aminophylline level365730009
- Aminophylline: blood level365731008
- Aminophylline: blood level - finding365731008
- Finding of aminophylline: blood level365731008
- Finding of serum aminophylline level365732001
- Serum aminophylline level365732001
- Serum aminophylline level - finding365732001
- Carbamazepine level365733006
- Carbamazepine level - finding365733006
- Finding of carbamazepine level365733006
- Finding of serum carbamazepine level365734000
- Serum carbamazepine level365734000
- Serum carbamazepine level - finding365734000
- Digoxin level365735004
- Digoxin level - finding365735004
- Finding of digoxin level365735004
- Finding of serum digoxin level365736003
- Serum digoxin level365736003
- Serum digoxin level - finding365736003
- Finding of lithium level365738002
- Lithium level365738002
- Lithium level - finding365738002
- Finding of blood lithium level365739005
- Lithium: blood level365739005
- Lithium: blood level - finding365739005
- Finding of serum lithium level365740007
- Serum lithium level365740007
- Serum lithium level - finding365740007
- Finding of phenobarbitone level365741006
- Phenobarbitone level365741006
- Phenobarbitone level - finding365741006
- Finding of serum phenobarbital level365742004
- Finding of serum phenobarbitone level365742004
- Serum phenobarbitone level365742004
- Serum phenobarbitone level - finding365742004
- Finding of phenytoin level365743009
- Phenytoin level365743009
- Phenytoin level - finding365743009
- Finding of serum phenytoin level365744003
- Serum phenytoin level365744003
- Serum phenytoin level - finding365744003
- Finding of valproate level365745002
- Valproate level365745002
- Valproate level - finding365745002
- Finding of serum sodium valproate level365746001
- Serum sodium valproate level365746001
- Serum sodium valproate level - finding365746001
- Inhaler technique - moderate390869002
- Nebuliser technique good391106002
- Nebulizer technique good391106002
- Nebuliser technique poor391107006
- Nebulizer technique poor391107006
- No nebulisation since last appointment401190001
- No nebulization since last appointment401190001
- Drug monitoring up to date408362004
- Medication monitoring up to date408362004
- Antihypertensive agent surveillance done709596006
- Antihypertensive medication surveillance done709596006
- Good response to medication1137679005
- Serum sodium valproate within therapeutic range1156005004
- Serum sodium valproate above therapeutic range1156006003
- Serum sodium valproate below therapeutic range1156007007
- Serum lithium level within therapeutic range1156020005
- Serum lithium level above therapeutic range1156021009
- Serum lithium level below therapeutic range1156022002
- Serum digoxin level above therapeutic range1156024001
- Serum digoxin level within therapeutic range1156025000
- Serum digoxin level below therapeutic range1156026004
- Serum phenytoin above therapeutic range1156043001
- Serum phenytoin within therapeutic range1156044007
- Serum phenytoin below therapeutic range1156045008
- Serum phenobarbital above therapeutic range1156056008
- Serum phenobarbitone above therapeutic range1156056008
- Serum phenobarbital below therapeutic range1156057004
- Serum phenobarbitone below therapeutic range1156057004
- Serum phenobarbital within therapeutic range1156058009
- Serum phenobarbitone within therapeutic range1156058009
- Serum carbamazepine above therapeutic range1156061005
- Serum carbamazepine below therapeutic range1156062003
- Serum carbamazepine within therapeutic range1156063008
- Acetaminophen within therapeutic range1172948006
- Paracetamol within therapeutic range1172948006
- Acetaminophen above therapeutic range1172949003
- Paracetamol above therapeutic range1172949003
- Salicylate above therapeutic range1187051004
- Salicylate below therapeutic range1187169005
- Serum aminophylline within therapeutic range1187175001
- Serum aminophylline above therapeutic range1187176000
- Serum aminophylline below therapeutic range1187177009
- Measurement of medication level in blood started448201000124101
- Medication dose changed432751000124106
- Medication dose changed in response to liver function453301000124104
- Medication dose changed in response to renal function453291000124100
- Medication dose changed to sliding scale453831000124103
- Medication dose changed too rapidly453461000124109
- Medication therapy changed too rapidly432361000124107
Clinical Terms
- No nebulization since last appointment
- Lithium: blood level - finding
- Therapeutic drug action
- Carbamazepine level above reference range
- Lithium level
- Drug action decreased
- Finding of serum phenytoin level
- Valproate level - finding
- Good response to medication
- Medication therapy changed too rapidly
- Pre-treatment uric acid level
- Serum aminophylline above therapeutic range
- Drug action reversal
- Serum phenobarbital above therapeutic range
- Finding of serum phenobarbitone level
- Finding of carbamazepine level
- Finding of serum lithium level
- Serum carbamazepine above therapeutic range
- Serum lithium level
- Serum phenytoin above therapeutic range
- Digoxin level
- Serum sodium valproate within therapeutic range
- Hormone replacement monitoring status
- Digoxin level below therapeutic range
- Finding of serum carbamazepine level
- Serum phenytoin level - finding
- Drug action increased
- Serum sodium valproate level - finding
- Drug effect increased
- Carbamazepine level below reference range
- Phenytoin level
- Paracetamol within therapeutic range
- Inhaler technique - moderate
- Lithium level therapeutic
- Serum phenobarbital below therapeutic range
- Finding of phenobarbitone level
- Phenobarbitone level above therapeutic range
- Finding of serum sodium valproate level
- Lithium: blood level
- Aminophylline level
- Carbamazepine level low
- Serum phenobarbitone within therapeutic range
- Phenothiazine injection - monitor
- Phenytoin level below reference range
- Gout monitoring status
- Serum carbamazepine within therapeutic range
- PEM completed
- Serum carbamazepine level
- Medication dose changed in response to liver function
- Nebulizer technique good
- No nebulisation since last appointment
- Serum lithium level within therapeutic range
- Warfarin monitoring status
- Lithium level - finding
- Lack of drug action
- Finding of aminophylline level
- Finding of phenytoin level
- Finding of valproate level
- Aminophylline: blood level
- Lack of drug effect
- Valproate level
- Paracetamol above therapeutic range
- Nebuliser technique poor
- Serum sodium valproate below therapeutic range
- Serum sodium valproate level
- Drug monitoring up to date
- Drug effect decreased
- Salicylate below therapeutic range
- Bronchodilators used more than once daily
- Salicylate above therapeutic range
- Finding of serum aminophylline level
- Drug action prolonged
- Drug action shortened
- Serum aminophylline level - finding
- Phenobarbitone level high
- Drug effect shortened
- Serum digoxin level - finding
- Serum carbamazepine below therapeutic range
- Phenobarbital level therapeutic
- Serum digoxin level above therapeutic range
- Hormone replacement monitoring check done
- Lithium level low
- Serum carbamazepine level - finding
- Medication dose changed
- Nebulizer technique poor
- Phenytoin level therapeutic
- Acetaminophen above therapeutic range
- Bronchodilators used a maximum of once daily
- Medication monitoring up to date
- Finding of digoxin level
- Prescription-event monitoring (PEM) completed
- Ineffective drug action
- Digoxin level low
- Serum lithium level below therapeutic range
- Digoxin level - finding
- Aminophylline level - finding
- Prescription event monitoring completed
- Phenytoin level above therapeutic range
- Finding of lithium level
- Serum phenytoin level
- Serum phenobarbitone below therapeutic range
- Serum phenobarbital within therapeutic range
- Serum phenobarbitone level - finding
- Finding of aminophylline: blood level
- Phenobarbitone level below therapeutic range
- Drug effect reversal
- Serum lithium level above therapeutic range
- Serum phenytoin within therapeutic range
- Therapeutic action of medication
- Bronchodilators used once daily
- Antihypertensive agent surveillance done
- Nebuliser technique good
- Phenobarbital level low
- Phenytoin level - finding
- Medication dose changed in response to renal function
- Serum digoxin level
- Finding of blood lithium level
- Phenobarbitone level low
- Asthma monitoring status
- Phenytoin level low
- Effects of immunotherapy
- Serum phenobarbitone level
- Antihypertensive medication surveillance done
- Carbamazepine level high
- Carbamazepine level
- Prescription event monitoring status
- Phenytoin level high
- Phenobarbitone level - finding
- Digoxin level above therapeutic range
- Aminophylline: blood level - finding
- Acetaminophen within therapeutic range
- Finding of serum phenobarbital level
- Lithium level below therapeutic range
- Serum aminophylline level
- Medication dose changed to sliding scale
- Phenobarbital level high
- Carbamazepine level therapeutic
- Digoxin level therapeutic
- Serum digoxin level below therapeutic range
- Serum aminophylline within therapeutic range
- Phenobarbitone level therapeutic
- Digoxin level high
- Serum phenobarbitone above therapeutic range
- Serum phenytoin below therapeutic range
- Phenobarbitone level
- Serum digoxin level within therapeutic range
- Serum aminophylline below therapeutic range
- Measurement of medication level in blood started
- Serum lithium level - finding
- Carbamazepine level - finding
- Inhaler technique - poor
- Therapeutic drug effect
- Serum sodium valproate above therapeutic range
- Drug effect prolonged
- Finding of serum digoxin level
- Intermittent drugs used more
- Medication dose changed too rapidly
Frequently Asked Questions
What is the ICD-10 code for encounter for therapeutic drug level monitoring?
The ICD-10-CM code for encounter for therapeutic drug level monitoring is Z51.81. The full clinical description is "Encounter for therapeutic drug level monitoring". Z51.81 is a billable/specific code that can be used on insurance claims and medical billing.
What does ICD-10 code Z51.81 mean?
ICD-10-CM code Z51.81 represents “Encounter for therapeutic drug level monitoring”. It is classified under Chapter 22: Factors Influencing Health Status and Contact With Health Services and is a billable/specific code that can be used on a claim.
Is Z51.81 a billable code?
Yes, Z51.81 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.
What chapter is Z51.81 in?
Z51.81 is in Chapter 22: Factors Influencing Health Status and Contact With Health Services (codes Z00-Z99).
What codes cannot be used with Z51.81?
Z51.81 has Excludes1 notes indicating codes that cannot be used together with it, including: follow-up examination after treatment (Z08-Z09); holiday relief care (Z75.5); encounter for blood-drug test for administrative or medicolegal reasons (Z02.83).
What SNOMED CT codes does Z51.81 map to?
Z51.81 maps to 91 SNOMED CT concepts: 1172949003, 1172948006, 365730009, 365731008, 709596006, and 86 more. SNOMED CT is a clinical terminology used in electronic health records.
What are the UMLS CUIs for Z51.81?
Z51.81 is linked to 1 UMLS Concept Unique Identifier: C2910943. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does Z51.81 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like encounter for therapeutic drug level monitoring affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of Z51.81?
There is no direct ICD-11 mapping available for Z51.81 in the WHO crosswalk tables. This may mean the concept is classified differently in ICD-11. Use the ICD-10 to ICD-11 converter to search for related codes.
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.