Chapter 3 of the outpatient coding and reporting guidelines emphasizes the correct usage of first-listed diagnoses in various outpatient scenarios, including surgery and routine medical visits. It highlights specific coding for chronic diseases, unconfirmed diagnoses, and various status codes, detailing how to categorize encounters appropriately. Additionally, it includes procedural coding requirements and guidelines for documenting patient conditions to ensure accurate and comprehensive reporting.

1. ASTEP-BY-STEPAPPROACH
1CD-10-CM OUTPATIENT
CODING AND REPORTING
GUIDELINES
Chapter 3
CODING 101
carol J. Buck | Jackie Grass Koesterman

2. chapter
HIGHLIGHTS
tOPICS
First Listed Diagnosis
Unconfirmed Diagnosis
Outpatient Surgery
Additional Diagnosis
Z-Codes
First-Listed Diagnosis and
Coexisting Conditions
Uncertain Diagnoses
Chronic Diseases
Documented Conditions
Diagnostic Services
Therapeutic Services
Preoperative Evaluation
Prenatal Visits
Chapter 3:1cd-10-cm outpatient coding and reporting guidelines

3. In the outpatient setting, the term first-listed diagnosis is used in lieu of
principal diagnosis.
general and disease specific guidelines take precedence over the outpatient
guidelines
OUTPATIENT SURGERY
outpatient surgery (same day surgery) - code the reason for the surgery
as the first-listed diagnosis even when surgery is not performed due to a
contraindication
OBSERVATION STAY
Admitted for observation for a medical condition - assign a code for the
medical condition as the first-listed diagnosis.
Presents for outpatient surgery and develops complications requiring
admission to observation - code the reason for the surgery as the first
reported diagnosis (reason for the encounter), followed by codes for the
complications as secondary diagnoses
CHIEF COMPLAINT- reason the for the visit from the patient's POV
FIrst-listed diagnosis
coding 101

4. OUTPATIENT SURGERY
code the reason for the
surgery as the first-listed
diagnosis (reason for the
encounter), even if the
surgery is not performed
due to a contraindication.
UNCONFIRMED
DIAGNOSIS
there are instances when
the diagnosis is discovered
after several encounters
report the signs or
symptoms that
occasioned the
encounter

5. Additional diagnosis
appropriate code(s) from A00.0 through T88.9, Z00-Z99
must be used to identify diagnoses, symptoms, conditions,
problems, complaints, or other reason(s) for the
encounter/visit
the documentation should describe the patient’s condition,
using terminology which includes specific diagnoses as well
as symptoms, problems, or reasons for the encounter
Codes that describe symptoms and signs, as opposed to
diagnoses, are acceptable for reporting purposes when a
diagnosis has not been established
1cd-10-cm outpatient coding and reporting guidelines

6. CODING 101
CONTACT/EXPOSURE
Z20- codes are for patients who do not show any sign
or symptom of a disease but are suspected to have
been exposed to it by close personal contact with an
infected individual or are in an area where a disease is
epidemic
Z77- indicates contact with and suspected exposures
hazardous to health
may be used as a first-listed code to explain an
encounter for testing OR secondary code to identify a
potential risk.
INOCULATIONSANDVACCINATIONS
indicates that a patient is being seen to receive a
prophylactic inoculation against a disease.
Procedure codes are required to identify the actual
administration of the injection and the type(s) of
immunizations given.
may be used as a secondary code if the inoculation is
given as a routine part of preventive health care,
Z-codes
used to classify persons who
are not currently sick when
they encounter health services
indicate a reason for an
encounter
not procedure codes
Categories:
Contact/ Exposure
Inoculations and
vaccinations
Status code

7. Status codes
CODING 101
indicate that a patient is either a carrier of a
disease or has the sequelae or residual of a
past disease or condition
status may affect the course of treatment and
its outcome
should not be used with a diagnosis code
from one of the body system chapters, if the
diagnosis code includes the information
provided by the status code
For encounters for weaning from a
mechanical ventilator, condition first then the
status.
Categories:
Genetic carrier
a person carries a gene, associated with a
particular disease, which may be passed to
offspring who may develop that disease.
Genetic susceptibility to disease
person has a gene that increases the risk
of that person developing the disease
should not be used as principal or first-
listed codes
Resistance to antimicrobial drugs
Estrogen receptor status
Retained foreign body fragments
Hormone sensitivity malignancy status
Asymptomatic HIV infection status
patient has tested positive for HIV but has
manifested no signs or symptoms of the
disease
Carrier of infectious disease
Underimmunization status
Pregnant state, incidental
secondary code only for use when the
pregnancy is in no way complicating the
reason for visit

8. Status codes
CODING 101
Do not resuscitate
DNR - order that allows you to choose
whether or not you want CPR in an
emergency
documented by the provider that a patient is
on do not resuscitate status at any time
during the stay
Blood type
Body mass index (BMI)
only assign when the associated diagnosis
(such as overweight or obesity) meets the
definition of a reportable diagnosis
Do not assign BMI codes during pregnancy.
Bed confinement status
Awaiting organ transplant status
Other specified health status
Code Z78.1, Physical restraint status, may be
used when it is documented by the provider
that a patient has been put in restraints
during the current encounter.
Long-term (current) drug therapy
indicate a patient’s continuous use of a
prescribed drug (including such things as
aspirin therapy) for the long-term treatment
of a condition or for prophylactic use.
not for use for patients who have addictions
to drugs
Assign the patient is receiving a medication
for an extended period as a prophylactic
measure, treatment of a chronic condition or
a disease requiring a lengthy course of
treatment.
Allergy status to drugs, medicaments and
biological substances

9. Status codes
CODING 101
Acquired absence of limb
Acquired absence of organs, not
elsewhere classified Allergy status, other
than to drugs and biological substances
Status post administration of tPA (rtPA)
in a different facility within the last 24
hours prior to admission to a current
facility
secondary diagnosis when a patient is
received by transfer into a facility and
documentation indicates they were
administered tissue plasminogen activator
(tPA) within the last 24 hours prior to
admission to the current facility
Artificial opening status
Transplanted organ and tissue status
Presence of cardiac and vascular
implants and grafts
Presence of other functional implants
Presence of other devices
Other postprocedural states
Assign code Z98.85, Transplanted organ
removal status, to indicate that a
transplanted organ has been previously
removed.
This code should not be assigned for the
encounter in which the transplanted
organ is removed
Dependence on enabling machines and
devices, not elsewhere classified

10. EXTERNAL CAUSE
INDEX
index classifies environmental
events, circumstances and other
adverse effects alphabetically
never reported as first listed
diagnosis
reported in addition to an injury
code
reported to clarify injuries or
adverse effects
Parts:
Code terms- describe the external
circumstance which the accident,
injury or act of violence occurred
Main terms- represent the type of
circumstance
Subterms- how the main term
occured
INDEX LOCATIONS
located at the end of the
tabular
Common terms:
z-codes
admissions
aftercare
attention
care
carrier
checking
contraception
counseling
dialysis
donor
examination
fitting
healthy
history of
maintenance
maladjustment
observation
problem
procedure
prophylactic
replacement
screening
status
supervision
test
transplant
unavailability
vaccination

11. Z-CODES
CIRCUMSTANCES TO ASSIGN Z
CODES
When a person not sick encounters the health services
for some specific purpose (organ donation, vaccination,
etc.)
Patient receives treatment for a specific disease or
injury
Circumstance or problem is present and influences a
patient's health status but not necessarily a disease
Indicate birth status and outcome of the delivery of a
newborn
1.
2.
3.
4.
Coding 101
HISTORY OFtwo types of history codes: Personal History Codes and
Family Codes
Personal code- explain a patient’s past medical condition that
no longer exists and is not receiving any treatment, but that
has the potential for recurrence, and therefore may require
continued monitoring
Family history- when a patient has a family member(s) who
has had a particular disease that causes the patient to be at
higher risk of also contracting the disease

12. FIRST-LISTED DIAGNOSIS
AND COEXISTING
CONDITIONS
First put the reason for encounter then
list all of the coexisting condition.
UNCERTAIN DIAGNOSESIf the diagnosis documented at the time of
discharge is qualified as “probable”,
“suspected”, “likely”, “questionable”,
“possible”, or “still to be ruled out”, or other
similar terms indicating uncertainty, code the
condition as if it existed or was established.
applicable only to inpatient admissions to short-
term, acute, long-term care and psychiatric
hospitals
CHRONIC DISEASES
Report the condition as many times as the
patient receives care or treatment for the
condition
DOCUMENTED CONDITIONS
Code all documented conditions that coexist
at the time of the encounter/visit
Do not code conditions that were previously
treated and no longer exist.
history codes may be used as secondary
codes if it has an impact on current care

13. DIAGNOSTIC SERVICES ONLY DURING AN ENCOUNTER/VISIT
sequence first the diagnosis, condition, problem, or other reason
for encounter/visit shown in the medical record to be chiefly
responsible for the outpatient services provided during the
encounter/visit then additional diagnoses
Diagnostic Services
provided to a patient during an encounter
ENCOUNTERSFORROUTINELABORATORY/RADIOLOGYTESTINGINTHE
ABSENCEOFANYSIGNS,SYMPTOMS,ORASSOCIATEDDIAGNOSIS
encounters for routine laboratory/radiology testing in the
absence of any signs, symptoms, or associated diagnosis
during the same encounter as a test to evaluate a sign,
symptom, or diagnosis-sign both the Z code and the code
describing the reason for the non-routine test.
OUTPATIENTENCOUNTERSFORDIAGNOSTICTESTSINTERPRETEDBYA
PHYSICIANANDAVAILABLEFINALREPORT
code any confirmed or definitive diagnosis(es) documented in
the interpretation
Do not code related signs and symptoms as additional
diagnoses.

14. Therapeutic services
first the diagnosis, condition, problem, or other reason for encounter/visit
shown in the medical record to be chiefly responsible for the outpatient
services provided during the encounter/visit
exception: chemotherapy or radiation therapy
preoperative evaluation
sequence first a code from subcategory Z01.81, Encounter for pre-procedural
examinations, to describe the pre-op consultations
Assign a code for the condition to describe the reason for the surgery as an
additional diagnosis.
1.
2.
coding 101
prenatal visits
Routine outpatient prenatal visits
code from category Z34, Encounter for supervision of normal pregnancy,
should be used as the first-listed diagnosis.
These codes should not be used in conjunction with chapter 15 codes.
Supervision of High-Risk Pregnancy
intended for use only during the prenatal period

15. CODING 101
Source:
Buck,C.J., Koesterman, J.G.(2019).
Buck's Step-by-Step Medical Coding,
2019 Edition. Elsevier Health
Sciences.
thank
you!