Income-tax treaties, tax residence and FICA are different regimes. U.S. services do not escape Social Security and Medicare merely because China pays the compensation, Chinese social insurance continues or an income-tax treaty applies.

1. U.S. services are the starting point for FICA

Resident aliens generally follow the same Social Security and Medicare rules as U.S. citizens for U.S. employment. Nonresident aliens performing services in the United States are also generally subject to FICA unless a specific visa, employment or international social-security exception applies. Payment location and currency do not automatically change the result.

Analyze each pay element and service period, documenting legal and common-law employer, work location, visa, residency start date and Payroll route. An income-tax treaty exemption or Form 8233 addresses its relevant income-tax withholding; it does not by itself establish a FICA exemption.

  • Actual service location
  • Resident or nonresident status
  • Visa category and authorized activity
  • Legal and common-law employer
  • Pay element and earning period

2. There is no effective U.S.-China totalization agreement as of the review date

The SSA's status page lists countries with current U.S. social-security agreements. As of July 18, 2026, China was not on that list. A China-U.S. assignee therefore cannot assume a bilateral totalization agreement or obtain a U.S.-China certificate of coverage that does not exist.

The employee may face Chinese social insurance and U.S. FICA at the same time, with Chinese liability determined under Chinese law. Model that possible dual cost, but do not treat inconvenience as a U.S. exemption. If the SSA list later changes, apply the actual effective date and covered period rather than assuming retroactive relief.

  • Check the official SSA list
  • Record the verification date
  • Separate income-tax and social-security treaties
  • Do not invent a certificate of coverage
  • Set a review for future agreement changes

3. Visa exceptions are narrow and can end

Certain F, J, M and Q nonresident aliens may qualify for a FICA exception while substantially complying with the visa purpose and performing authorized services. It is not a universal exemption for foreign students, researchers or dependents, and it may end when the individual becomes a resident, changes status or performs unauthorized work.

H-1B status generally does not receive that student-category exception. IRS guidance states that H-1B wages for U.S. services are generally subject to FICA unless another rule applies. Payroll needs the current visa, I-94, entry history and residence calculation rather than nationality alone.

  • Visa category and validity
  • Whether employment is authorized
  • Substantial Presence Test status
  • Status or employer change date
  • Payroll exemption start and stop dates

4. Assignment design and shadow Payroll must connect to FICA

When the China entity pays cash and recharges a U.S. entity, common-law employment and U.S. services may still require U.S. Payroll reporting. Shadow Payroll can bring offshore salary, bonus and benefits into the U.S. calculation, but it must avoid duplication with local pay and assign deposit and filing responsibility.

Tax equalization, housing, relocation, equity and other benefits may affect wages under specific rules. The intercompany invoice, assignment letter, Payroll register and ledger should explain gross compensation and FICA differences, not merely reconcile net cash paid.

  • Home and host Payroll data handoff
  • Offshore salary and benefits
  • Tax equalization or gross-up
  • Intercompany recharge
  • Forms 941 and W-2 to the ledger

5. Reassess every status change

Prepare a pre-assignment FICA memo covering location, status, exception, effective date, Payroll setup and reviewer. Visa conversion, residence, U.S. employment, extension and departure should each trigger an update; an onboarding conclusion cannot govern the entire assignment without review.

Quarterly, reconcile the home-payroll feed, U.S. Payroll, Form 941, FICA deposits and ledger. For a historical shortfall, establish workers, periods and wage base before considering Forms 941-X and W-2c, employee recovery or employer cost, together with related state Payroll corrections.