Primary Care CPT, ICD-10 & Diagnostic Codes Cheat Sheet

A practical reference guide covering E/M codes, preventive exam codes, common ICD-10 diagnosis codes, common procedures, and documentation best practices for primary care and family medicine.

By AJ Pakpour — The Business of Modern Medicine™

Educational Summary

This reference guide covers the most commonly used CPT and ICD-10 codes in primary care and family medicine practice. It includes E/M code levels (99202–99215) with time ranges, preventive exam codes (99381–99404), common ICD-10 diagnosis codes across major categories (hypertension, diabetes, hyperlipidemia, hypothyroidism, depression, respiratory, musculoskeletal, GI, cardiovascular, obesity, and more), common procedures, and documentation best practices. All codes and descriptions are provided for educational reference only. Verify current codes, coverage, and payment with CMS, your payer contracts, and a qualified billing professional.

Key Takeaways

• ✓E/M codes 99202–99215 are determined by medical decision making (MDM) or total time on the date of the encounter
• ✓New patient E/M codes: 99202 (15–29 min), 99203 (30–44 min), 99204 (45–59 min), 99205 (60–74 min)
• ✓Established patient E/M codes: 99211 (nurse visit), 99212–99215 (problem-focused through comprehensive)
• ✓Preventive exam codes differ for new vs. established patients and by age range
• ✓Documentation must link diagnosis codes to findings, assessment, and plan
• ✓Time + MDM = your E/M level — use the method that best supports the documented encounter