Sometimes payer guidelines differ from the official guidelines; this can be confusing. Let’s look at a sequencing priority, for example, in Chapter 15: Pregnancy, Childbirth, and the Puerperium (o00-o9A).  The ICD-10-CM official guidelines tell us how to code based on the provider's documentation; in addition, it is important to know Chapter 15 codes are never to be used on newborn records, only on the maternal record.  Keep in mind some conditions and co-morbidities are required to be coded together; watch for code notes.  If a payer has a policy that is different from the guidelines, be sure to follow their rules and guidelines when coding if you have a contractual agreement with them. Find-A-Code will sequence codes according to the ICD-10-CM guidelines first.  

Trimester
The Trimester is included in most of the codes listed in Chapter 15.  If it is not included, it is due to the condition always occurring in a specific trimester or the concept of the trimester of pregnancy is not applicable according to the guidelines. Trimesters are based on the provider's documentation for the number of weeks and trimesters are counted from the first day of the last menstrual period.

Defined as follows:

1st trimester- less than 14 weeks 0 days

2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days

3rd trimester- 28 weeks 0 days until delivery

NOTE: Since the weeks of gestation includes full weeks, the full week is not reported until a complete 7 days put the patient into the full week.  For example, a full week is not reported at 39 weeks and 6 days; in this case, 39 weeks should be assigned.

Hospital Admission – Reporting the Correct Trimester
If a patient is admitted to the hospital for a condition related to her pregnancy, and the trimester changes (according to the rules above), the trimester is based on the weeks the patient was admitted not discharged.  

Guidelines 15.a.1) state, “Chapter 15 codes have sequencing priority over codes from other chapters. Additional codes from other chapters may be used in conjunction with chapter 15 codes to further specify conditions. Should the provider document that the pregnancy is incidental to the encounter, then code Z33.1, pregnant state, incidental, should be used in place of any chapter 15 codes. It is the provider’s responsibility to state that the condition being treated is not affecting the pregnancy.

15.b. Selection of OB Principal or First-listed Diagnosis
1) Routine outpatient prenatal visits:  For routine outpatient prenatal visits when no complications are present, a 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.

2) Supervision of High-Risk Pregnancy Codes from category O09: Supervision of high-risk pregnancy is intended for use only during the prenatal period. For complications during the labor or delivery episode as a result of a high-risk pregnancy, assign the applicable complication codes from Chapter 15. If there are no complications during the labor or delivery episode, assign code O80, encounter, for a full-term uncomplicated delivery. For routine prenatal outpatient visits for patients with high-risk pregnancies, a code from category O09, supervision of high-risk pregnancy, should be used as the first-listed diagnosis. Secondary chapter 15 codes may be used in conjunction with these codes if appropriate.

When no Delivery Occurs

If no delivery occurs, the complication is assigned as the principal diagnosis; for more than one complication, any of the complication codes can be listed first.

15.b.4) When delivery Occurs
When an obstetric patient is admitted and delivers during that admission, the condition that prompted the admission should be sequenced as the principal diagnosis. If multiple conditions prompted the admission, sequence the one most related to the delivery as the principal diagnosis. A code for any complication of the delivery should be assigned as an additional diagnosis. In cases of cesarean delivery, if the patient was admitted with a condition that resulted in the performance of a cesarean procedure, that condition should be selected as the principal diagnosis. If the reason for the admission was unrelated to the condition resulting in the cesarean delivery, the condition related to the reason for the admission should be selected as the principal diagnosis.

Outcome of Delivery using Z37
The outcome of delivery is assigned on every maternal record when a delivery has occurred, the outcome of delivery is only reported on the maternal record, never on the newborn record.  

There are many other guidelines not covered here; these can be viewed on Find-A-Code under ICD-10-CM Official Guidelines for Coding and Reporting.