FY2027 ICD-10-CM reference
O09.521: Supervision of elderly multigravida, first trimester
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Supervision of elderly multigravida, first trimester. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Billable code. Verified against the official FY2027 order file.
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
CODES FROM THIS CHAPTER ARE FOR USE ONLY ON MATERNAL RECORDS, NEVER ON NEWBORN RECORDS
Source: O00-O9A (chapter, inherited).
Instructional note
Codes from this chapter are for use for conditions related to or aggravated by the pregnancy, childbirth, or by the puerperium (maternal causes or obstetric causes)
Source: O00-O9A (chapter, inherited).
Instructional note
Trimesters are counted from the first day of the last menstrual period. They are defined as follows:
Source: O00-O9A (chapter, inherited).
Instructional note
1st trimester- less than 14 weeks 0 days
Source: O00-O9A (chapter, inherited).
Instructional note
2nd trimester- 14 weeks 0 days to less than 28 weeks 0 days
Source: O00-O9A (chapter, inherited).
Instructional note
3rd trimester- 28 weeks 0 days until delivery
Source: O00-O9A (chapter, inherited).
Instructional note
code, if applicable, from category Z3A, Weeks of gestation, to identify the specific week of the pregnancy, if known.
Source: O00-O9A (chapter, inherited).
Excludes1
supervision of normal pregnancy (Z34.-)
Source: O00-O9A (chapter, inherited).
Excludes2
mental and behavioral disorders associated with the puerperium (F53.-)
Source: O00-O9A (chapter, inherited).
Excludes2
obstetrical tetanus (A34)
Source: O00-O9A (chapter, inherited).
Excludes2
postpartum necrosis of pituitary gland (E23.0)
Source: O00-O9A (chapter, inherited).
Excludes2
puerperal osteomalacia (M83.0)
Source: O00-O9A (chapter, inherited).
Instructional note
Pregnancy for a female 35 years and older at expected date of delivery
Source: O09.5 (self, inherited).
Compare the FY2027 additions, removals and billable-status changes
What does O09.521 mean in FY2027?
The official ICD-10-CM descriptor is Supervision of elderly multigravida, first trimester. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is O09.521 billable in FY2027?
The FY2027 order file marks O09.521 as billable. Check the complete Tabular instructions and documentation before assigning it.
Does O09.521 map to an HCC?
O09.521 has no CMS-HCC V28 category in the CMS 2027 Initial ICD-10-CM Mappings (payment year 2027, 2026 dates of service). ESRD, RxHCC, PACE and HHS-HCC mappings are still pending verification for FY2027.
Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.
Review the FY2026 April edition